Ignore repo changes for Git sourcedataMatches()

Git is more than willing to fetch branches from completely unrelated
repositories into the same local repository (it'll give a warning about
'no related commits', but that's not a problem). There's no reason to
throw away the current repository and re-clone just because the repo
changed (and it saves a lot of time if the different remotes are
actually just different clones of the same project).

slave/buildslave/commands/git.py

@@ -85,8 +85,6 @@ def _dovccmd(self, command, cb=None, **kwargs):
     def sourcedataMatches(self):
         try:
             olddata = self.readSourcedata()
-            if not olddata.startswith(self.repourl+' '):
-                return False
         except IOError:
             return False
         return True