Don't apply strict parsing rules to stable branches.
Don't apply strict parsing rules to stable branches.

Reasoning is:
 - devstack etc protect us from functional issues
 - we're backporting to stable, so guarding against
   aesthetics and DRY concerns is not our business anymore
 - if in future we have other not-functional linty style
   things to add, we don't want them to affect stable
   either.

Change-Id: I8e891b8fdb6acfdf5e7e084467ee8596f51c251a

noorul/os-project-config,coolsvap/project-config,Tesora/tesora-project-config,dongwenjuan/project-config,anbangr/osci-project-config,openstack-infra/project-config,noorul/os-project-config,Tesora/tesora-project-config,coolsvap/project-config,openstack-infra/project-config,dongwenjuan/project-config,anbangr/osci-project-config