Please create a tor-messenger.git repo

To maintain a fork of https://hg.mozilla.org/releases/comm-esr45/ similar to tor-browser.git

We've got a number of patches which are becoming unwieldy, https://gitweb.torproject.org/tor-messenger-build.git/tree/projects/instantbird

Most likely, Mozilla will handle the hg => git sync in, https://bugzilla.mozilla.org/show_bug.cgi?id=1309045

but otherwise, I'll do it. Thanks!

Oh, and please grants access to the tormessenger group.