Nil pointer on starting vpn-client

[ersonp]

Describe the bug
invalid memory address or nil pointer dereference panic is seen in vpn-client when starting. This seems to happen when the connection to dmsg is lost

Environment information:

• OS: docker image
• Platform: k8s

2022/03/16 13:33:33 [lke31049-46687-60e7964454d2/DGadhYabIG-000124] "GET http://localhost:8000/api/visors/038932d71a4c065f6ed627a3f5e274cb5918fa0e9a59cf98781cef4d32a2d3c422/summary HTTP/1.1" from 127.0.0.1:57678 - 200 1790B in 26.368065ms
[2022-03-16T13:33:34Z] INFO [visor]: Changing vpn-client password to ""
[2022-03-16T13:33:34Z] INFO [visor:config]: Flushing config to file. config_version="v1.1.1" filepath="/etc/skywire/skywire-visor.json"
[2022-03-16T13:33:34Z] INFO [visor]: Updated vpn-client password
[2022-03-16T13:33:34Z] INFO [visor]: Changing vpn-client PK to "038932d71a4c065f6ed627a3f5e274cb5918fa0e9a59cf98781cef4d32a2d3c422"
[2022-03-16T13:33:34Z] INFO [visor:config]: Flushing config to file. config_version="v1.1.1" filepath="/etc/skywire/skywire-visor.json"
[2022-03-16T13:33:34Z] INFO [visor]: Updated vpn-client PK
2022/03/16 13:33:34 [lke31049-46687-60e7964454d2/DGadhYabIG-000125] "PUT http://localhost:8000/api/visors/038932d71a4c065f6ed627a3f5e274cb5918fa0e9a59cf98781cef4d32a2d3c422/apps/vpn-client HTTP/1.1" from 127.0.0.1:57678 - 200 83B in 31.226105ms
[2022-03-16T13:33:34Z] INFO [dmsg_trackers]: failed to re-create dmsgtracker client error="dmsg error 100 - entry is not found in discovery"
[2022-03-16T13:33:34Z] INFO [dmsg_trackers]: failed to re-create dmsgtracker client error="dmsg error 100 - entry is not found in discovery"
2022/03/16 13:33:34 [lke31049-46687-60e7964454d2/DGadhYabIG-000126] "GET http://localhost:8000/api/visors/038932d71a4c065f6ed627a3f5e274cb5918fa0e9a59cf98781cef4d32a2d3c422/summary HTTP/1.1" from 127.0.0.1:57678 - 200 1875B in 22.010837ms

 panic: runtime error: invalid memory address or nil pointer dereference
 
 -> github.com/skycoin/skywire/pkg/transport.(*Manager).STCPRRemoteAddrs
 ->   /skywire/pkg/transport/manager.go:463

    github.com/skycoin/skywire/pkg/visor.(*Visor).StartApp
      /skywire/pkg/visor/api.go:315
    github.com/skycoin/skywire/pkg/visor.(*Hypervisor).putApp.func1
      /skywire/pkg/visor/hypervisor.go:679
    github.com/skycoin/skywire/pkg/visor.(*Hypervisor).withCtx.func1
      /skywire/pkg/visor/hypervisor.go:1416
    net/http.HandlerFunc.ServeHTTP
      /usr/local/go/src/net/http/server.go:2046
    github.com/go-chi/chi/v5.(*ChainHandler).ServeHTTP
      /skywire/vendor/github.com/go-chi/chi/v5/chain.go:31
    github.com/go-chi/chi/v5.(*Mux).routeHTTP
      /skywire/vendor/github.com/go-chi/chi/v5/mux.go:444
    net/http.HandlerFunc.ServeHTTP
      /usr/local/go/src/net/http/server.go:2046
    github.com/go-chi/chi/v5/middleware.Timeout.func1.1
      /skywire/vendor/github.com/go-chi/chi/v5/middleware/timeout.go:45
    net/http.HandlerFunc.ServeHTTP
      /usr/local/go/src/net/http/server.go:2046
    github.com/go-chi/chi/v5.(*Mux).ServeHTTP
      /skywire/vendor/github.com/go-chi/chi/v5/mux.go:73
    github.com/go-chi/chi/v5.(*Mux).Mount.func1
      /skywire/vendor/github.com/go-chi/chi/v5/mux.go:316
    net/http.HandlerFunc.ServeHTTP
      /usr/local/go/src/net/http/server.go:2046
    github.com/go-chi/chi/v5.(*Mux).routeHTTP
      /skywire/vendor/github.com/go-chi/chi/v5/mux.go:444
    net/http.HandlerFunc.ServeHTTP
      /usr/local/go/src/net/http/server.go:2046
    github.com/go-chi/chi/v5.(*Mux).ServeHTTP
      /skywire/vendor/github.com/go-chi/chi/v5/mux.go:73
    github.com/go-chi/chi/v5.(*Mux).Mount.func1
      /skywire/vendor/github.com/go-chi/chi/v5/mux.go:316
    net/http.HandlerFunc.ServeHTTP
      /usr/local/go/src/net/http/server.go:2046
    github.com/go-chi/chi/v5.(*Mux).routeHTTP
      /skywire/vendor/github.com/go-chi/chi/v5/mux.go:444
    net/http.HandlerFunc.ServeHTTP
      /usr/local/go/src/net/http/server.go:2046
    github.com/skycoin/skywire-utilities/pkg/httputil.SetLoggerMiddleware.func1.1
      /skywire/vendor/github.com/skycoin/skywire-utilities/pkg/httputil/httputil.go:99
    net/http.HandlerFunc.ServeHTTP
      /usr/local/go/src/net/http/server.go:2046
    github.com/go-chi/chi/v5/middleware.Recoverer.func1
      /skywire/vendor/github.com/go-chi/chi/v5/middleware/recoverer.go:43
    net/http.HandlerFunc.ServeHTTP
      /usr/local/go/src/net/http/server.go:2046
    github.com/go-chi/chi/v5/middleware.RequestLogger.func1.1
      /skywire/vendor/github.com/go-chi/chi/v5/middleware/logger.go:57
    net/http.HandlerFunc.ServeHTTP
      /usr/local/go/src/net/http/server.go:2046
    github.com/go-chi/chi/v5/middleware.RealIP.func1
      /skywire/vendor/github.com/go-chi/chi/v5/middleware/realip.go:36
    net/http.HandlerFunc.ServeHTTP
      /usr/local/go/src/net/http/server.go:2046
    github.com/go-chi/chi/v5/middleware.RequestID.func1
      /skywire/vendor/github.com/go-chi/chi/v5/middleware/request_id.go:76
    net/http.HandlerFunc.ServeHTTP
      /usr/local/go/src/net/http/server.go:2046
    github.com/go-chi/chi/v5.(*Mux).ServeHTTP
      /skywire/vendor/github.com/go-chi/chi/v5/mux.go:90
    net/http.serverHandler.ServeHTTP
      /usr/local/go/src/net/http/server.go:2878
    net/http.(*conn).serve
      /usr/local/go/src/net/http/server.go:1929
    created by net/http.(*Server).Serve
      /usr/local/go/src/net/http/server.go:3033