Force reviewday ssh to gerrit to use ipv4

Running into issues running reviewday over ipv6 on static
server, updated ssh config forcing it to use only ipv4 for
ssh for now.

Change-Id: I79e0b9271ff64e09bd41b1f1fbaf18eb3f90a1c4
Reviewed-on: https://review.openstack.org/29029
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Approved: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Tested-by: Jenkins