[CVE-2018-1000115] memcached: restrict to TCP

https://access.redhat.com/security/cve/cve-2018-1000115

Restrict Memcached to only work on TCP.
The configuration only binds memcached on localhost but in case it
changes, we'll prevent DDoS amplification attacks.

Change-Id: Ib87b41b9f22549ec49788721b5806c972f3c5d2f

manifests/memcached.pp

@@ -2,6 +2,7 @@ class openstack_integration::memcached {
   include ::openstack_integration::config
 
   class { '::memcached':
-    listen_ip => $::openstack_integration::config::host
+    listen_ip => $::openstack_integration::config::host,
+    udp_port  => 0,
   }
 }