removing xmpp chat

The server-side xmpp service is down forever, so I am thinking to remove xmpp chat from the UI. This also makes mobile view cleaner.

I tried this patch but it messed up the whole webpage: https://github.com/ccding/Rowell/commit/e3b7c6b6240f12d48386c20256953c0b7f0f2636

Any suggestions?