Survey missing on rare occasions

[0pcom]

a situation has recently come to my attention where visors may have the reward address set, but the survey is not there, for whatever reason.

The exact cause is pending investigation, however from a system design standpoint, it's clear that while using a static file is faster to collect the surveys, the nature of the survey being served over dmsghttp by the log server is dependent upon and may be disrupted by unforseen events and forces.

I suggest as a solution to this, an endpoint for the dmsghttp log server, /node-info which will generate the survey and serve it, regardless of the reward address having been set or not, and only to the whitelisted keys which are granted access to the survey.

While this will certainly be slower to respond, it's necessary to have this as a backup means of collecting the survey in case of issues with the file server, for purposes of reward calculation and distribution.

[0pcom]

workaround implemented in #1579