Fixed referenced before assignment in zuul module

It was using a non-defined url variable and failed to me when running a
simple jenkins-jobs test -o ../outdir .

Change-Id: I56e6376de4972ea0f64bd8c81d6eb6d8f7f6d497
Signed-off-by: David Caro <dcaroest@redhat.com>
Merge "Fixed referenced before assignment in zuul module"