Git does not automatically reconnect after connection failure

If you sever the connection between Fisheye and a remote Git repository, it won't reconnect until the repository is manually restarted.

Steps to reproduce:

1. Add a new remote Git repo to Fisheye, allow it to index.
2. Stop the remote Git repo.
3. Allow the poller to run and throw a connection issue.
4. Restart the remote Git repo.
5. Notice that Fisheye doesn't reconnect the repository.