In check queue there were 2 iptables_hybrid jobs. One was run on Ubuntu
and one on Fedora.
During the Shanghai PTG we agreed to remove one of those jobs and left
only one of them to be run in both check and gate queues.
This commit removes iptables_hybrid job based on Fedora image.
Fedora jobs also make less sense for stable branches
Change-Id: If0adb7ca4e254f5b19375b471679bcc18e0c7790
(cherry picked from commit a2fdf8aa72)
c36f1fc292