Just clean original config

Original config file should not be deleted but only cleaned,
so that it is not recreated during package update.

Change-Id: I8ead90fd92c20dc7ebeadbb9134a6c21a52d3481
Closes-Bug: 1347533
Closes-Bug: rhbz#1122192
Allow array in cache_server_ip

If we use multiple memcached servers, we can specify an array of IP addresses
to use rather than just one.  This also allows a string, for one memcached
server and for backwards compatibility.

Change-Id: I2f94a36a63f64678581e240244f70a6d4cad1ee5