Handle cases when the remote is not yet setup.

Author: guyzmo

git_repo/services/ext/gerrit.py

@@ -147,7 +147,10 @@ def request_fetch(self, user, repo, request, pull=False, force=False):
         else:
             change_id = request.split('/')[3]
 
-        remote = self.repository.remote(self.name)
+        try:
+            remote = self.repository.remote(self.name)
+        except ValueError as err:
+            raise Exception('Remote "{remote}" is not setup. Please run `git {remote} add`'.format(remote=self.name))
         local_branch_name = 'requests/{}/{}'.format(self.name, change_id)
         self.fetch(remote, request, local_branch_name, force=force)