Remove defaults for get_gitbuilder_hash args
Remove defaults for get_gitbuilder_hash args

http://tracker.ceph.com/issues/16838
Fixes: 16838

Signed-off-by: Zack Cerza <d7cdf09fc0f0426e98c9978ee42da5d61fa54986@redhat.com>

dmick/teuthology,SUSE/teuthology,ceph/teuthology,ktdreyer/teuthology,SUSE/teuthology,ktdreyer/teuthology,ceph/teuthology,SUSE/teuthology,dmick/teuthology,dmick/teuthology