Jenkins broken after upgrade 

Hi @mfournier,

Jenkins was stuck today. I tried to fix this by upgrading to the newest (packaged) version and very nearly broke it all (it wouldn't come up again because the Github OAuth plugin ran into a null-pointer exception during start-up). It's running again, but it appears that it can still not spawn any workers on DigitalOcean. Could you take a look?

Thanks and best regards,
—octo