Change to using the SSH url; git urls cannot be used with private repos on GitHub

endpoints/trigger.py

@@ -811,7 +811,7 @@ class GithubBuildTrigger(BuildTriggerHandler):
       'commit_sha': commit_sha,
       'ref': ref,
       'default_branch': repo.default_branch,
-      'git_url': repo.git_url,
+      'git_url': repo.ssh_url,
     }
 
     # add the commit info.