Adding python-memcache to contrail-openstack-config dependency of juno

The issue is seen in juno after updating the keystonemiddleware package
version used in juno, fixing it in control.in for juno.

The latest keystonemiddleware contrail-config uses keystonemiddleware to authenticate with keystone.
keystonemiddleware has a dependency on memcache, but the dependency is
not defined in the upstream keystonemiddleware package.
Adding the dependency in contrail-openstack-config as the config node
needs memcache installed while using keystonemiddleware.

Change-Id: Ie228f37358df1c699859b8b3cb6b26a62893acf2
Closes-Bug: #1602618

common/debian/contrail-openstack-config/debian/control.in

@@ -28,5 +28,7 @@ Depends:
  python-bottle,
  ifmap-python-client,
  contrail-config-openstack,
- keepalived (=1:1.2.13-1~bpo70+1) | keepalived (=1.2.13-0~276~ubuntu14.04.1)
+ keepalived (=1:1.2.13-1~bpo70+1) | keepalived (=1.2.13-0~276~ubuntu14.04.1),
+ memcached,
+ python-memcache
 Description: Contrail Openstack Config composite debian package