Fix signal handler.

Change-Id: Idf4c576d6f6576519f1deff85ccc3f3901491d0e
Reviewed-on: https://review.openstack.org/33463
Reviewed-by: Monty Taylor <mordred@inaugust.com>
Approved: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins