Bug 774585 changed the way that GetCodebasePrincipal works (see https://bugzilla.mozilla.org/show_bug.cgi?id=774585#c0).
Thunderbird uses GetCodebasePrincipal in 3 locations:
line 46 -- var principal = ssm.getCodebasePrincipal(uri);
line 54 -- let principal = secMan.getCodebasePrincipal(aURI);
line 1205 -- let principal = ssm.getCodebasePrincipal(uri);
These need to be updated to fix Account Provisioner and our About Redirector.
Cc'ing some SeaMonkey people, because I think suite is affected too.
(Note that this is part of what's causing all of our current Mozmill oranges on comm-central)
Landed fix with r=bustage-fix in comm-central as https://hg.mozilla.org/comm-central/rev/e3a1e30473f1
Again, you SeaMonkey folks might want to do something similar in suite.