[Bug]: Profile VNC connection fails while profile browser is still running (was: Profile ping returning success after expired)

[SuaYoo]

Browser profiles sometimes shows an empty gray screen instead of a "reload" dialog. This is due to the /ping endpoint returning success: true even after the profile is expired.

[ikreymer]

At first, it seemed that the profile may have expired, but actually the browser is still running, but the VNC connection / websocket to the profile seems to be failing to go through.
After one such example, restarting x11vnc on the crawler seemed to fix the issue.
This happened with 'long-running' profile browsers, which maybe should not be allowed.