healthcheck/memcached: add brackets if ipv6

If memcached is deployed to listen on a IPv6 address, the healthcheck
command needs to be run with the right argument and the host needs
brackets.

Change-Id: I9244514d8686f72b0c47aef333a005ff61ddfdf6

healthcheck/memcached

@@ -1,5 +1,11 @@
 #!/bin/bash
 
 listen_addr=$(awk 'match($0, /-l +([0-9a-fA-F\.\:]+) /, a) {print a[1]}' /etc/sysconfig/memcached)
+
+# Add brackets if IPv6
+if [[ $listen_addr =~ ":" ]]; then
+  listen_addr="[${listen_addr}]"
+fi
+
 echo "stats" | socat - TCP:$listen_addr:11211
 exit