An unexpected error occurred while reading an extension's comments

[vitorfg8]

Describe the bug
App crashed after clicking "Show All Reviews" on an extension

System Information:

• Distro: Fedora
• Extension Manager version: 0.4.2
• Package format: Flatpak

Additional context

Support Log
----
Version: 0.4.2
Development: No
Package Format: Unknown Package
Status: Official
----
../src/exm-backtrace.c:79 'exm_backtrace_print'
../src/main.c:41 'handler'
(null):0 '(null)'
(null):0 '(null)'
../src/exm-comment-dialog.c:139 'on_get_comments'
(null):0 '(null)'
(null):0 '(null)'
../src/web/exm-request-handler.c:80 'request_callback'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
(null):0 '(null)'
../src/main.c:109 'run_app'
(null):0 '(null)'
(null):0 '(null)'
../sysdeps/x86_64/start.S:115 '(null)'
(null):0 '(null)'

[mjakeman]

Let's track it in #495

Duplicate of #495