Ignore iptables-save fails

iptables-save command is used for log iptables rules in case ssh
connection error. It could not exist in tempest env, also there is
no much sense running it in isolated tempest container.
Lets ignore errors for iptables-save.

Related-PRODX: PRODX-56262
Change-Id: I9d35dd584541b4d4f7932787bce88447ea5a66fd
1 file changed