Fix CVMFS deployment of tags

I realized that our deployment of tagged versions to CVMFS actually never worked - however, the job returned with no error. The reason for the former was a mismatch between the naming scheme of our tagged version (X.Y.Z) versus the naming scheme of the actual tag (vX.Y.Z). The latter was caused by a badly written script (by me).

I now fixed this by manually removing the v from the tag name when deploying. This way, everything stays as it was and we continue naming our tags the same way.

I also tried to add an exit code to catch future failures of similar nature.

Since two tags have been published since I did the unthinkable and altered them, adding above changes on top of them and replaced the original tags. I do think the impact of this is minor as no program code is changed but merely infrastructure scripts. This allowed the CI to correctly process the tag pipelines and to deploy the missing version to CVMFS.