jobs/osmocom-obs.yml: set default git branch

I was quite surprised, that the job used "osmith/pdfs-in-doc-subpackage"
instead of "master" today [1]. Fix this randomness by adding a branch
parameter that defaults to "master".

Interestingly, we have to set the default branch to
"refs/remotes/origin/master". When using "*/master" (like we do in other
jobs), Jenkins would still chose my branch over "origin/master", even
though mine does not have "master" in the name. I have also tried
"chosing-strategy: 'default'", in case it was using the gerrit strategy
for some reason (like in [2]), and setting 'refspec:', but both did not
have any effect.

[1] https://jenkins.osmocom.org/jenkins/job/Osmocom_OBS_nightly/98/
[2] https://issues.jenkins-ci.org/browse/JENKINS-26981

Change-Id: I6d1f0e70d5c82ffd551d00ffdf2712cbfaec16cf

0 files changed, 0 insertions, 0 deletions