clone.sh: Skip cloning if dependency repo is not defined

If dependency repo URL is not defined in a Jenkins job, it means that
this dependency is not necessary in current job. So skip cloning this
dependency repo in current job to save resources.

Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
Change-Id: Ib6d07b14658b36184e982c64f2b1f7a38cc4e8c7
1 file changed