Doesn't log errors due to missing credentials

[sjoerdsimons]

A common mistake when setting up jobs for the obs gitlab runner is forgetting to set teh required env vars for user/password/server. unfortunately it seems the released version of the runner ends up not pushing those back those errors to gitlab, it's only visible on the stdout logs.

This doesn't help for end-users who just say a "job failed" error with no further information

[refi64]

#9 has some code for this but tied to the other changes within.