Retry on certificate pinning error

[alexforencich]

Certificate key pinning problems should allow an option to "retry" instead of forcing the proton mail bridge to exit. This is occasionally a problem when connecting to captive portals - once the "sign in" process is complete, the bridge should be able to connect properly. But, the only option is to quit the bridge and then manually go restart it, which is rather annoying.

Expected Behavior

When a certificate key pinning problem occurs, don't completely break the application, instead retry periodically, similar to the automatic reconnect when the connection is lost.

Current Behavior

When a certificate key pinning problem occurs, the bridge application halts and has to be manually restarted.

Possible Solution

Either perform an automatic retry and clear the dialog box when the problem is cleared, or add a button to manually trigger a retry alongside the button to exit the bridge. Alternatively, remove the dialog box completely and instead put up a status message, similar to the "offline" status, and periodically retry in the background.

Steps to Reproduce

1. Connect to a captive portal that triggers a certificate pinning error

Version Information

v3.12.0