Fix jenkins link in running-tests

The previous link doesn't exist anymore, using new link instead.

Change-Id: I6d24faee6fe5b5984c9152168c6dac44135f8414

doc/running-tests.rst

@@ -103,4 +103,4 @@ For more information see the `oslotest documentation
 
 .. rubric:: Footnotes
 
-.. [#f1] See http://docs.openstack.org/infra/system-config/jenkins.html
+.. [#f1] See https://docs.openstack.org/infra/system-config/jjb.html