Adjust virtual-mcp11-aio/openstack/init.yml for pike

This patch changes virtual-mcp11-aio/openstack/init.yml in order to deploy Pike

Change-Id: I2b62591884cfd524ca6bfa2534432a0d6dca524a
diff --git a/classes/cluster/virtual-mcp11-aio/init.yml b/classes/cluster/virtual-mcp11-aio/init.yml
index 614dfd3..2c9788b 100755
--- a/classes/cluster/virtual-mcp11-aio/init.yml
+++ b/classes/cluster/virtual-mcp11-aio/init.yml
@@ -58,6 +58,10 @@
           - pin: ${_param:linux_system_repo_pin}
             priority: ${_param:linux_system_repo_priority}
             package: '*'
+        # workaround for PROD-15657, mysql 5.7 isn't built, using 5.6 instead
+          - pin: 'version 5.6*'
+            priority: 1300
+            package: 'mysql-client'
     network:
       bridge: openvswitch
       interface: