Reset auth_data when called for an invalid connection
Reset auth_data when called for an invalid connection

Change-Id: Icd9d8b14e51e12348f2702f1ea60bf543a6255d6
Reviewed-on: http://review.couchbase.org/38690
Reviewed-by: Michael Wiederhold <a17fed27eaa842282862ff7c1b9c8395a26ac320@couchbase.com>
Tested-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@gmail.com>

daverigby/kv_engine,daverigby/memcached,cloudrain21/memcached-1,daverigby/kv_engine,cloudrain21/memcached-1,mrkwse/memcached,mrkwse/memcached,daverigby/memcached,daverigby/kv_engine,jimwwalker/memcached,mrkwse/memcached,daverigby/kv_engine,cloudrain21/memcached-1,jimwwalker/memcached,jimwwalker/memcached,owendCB/memcached,couchbase/memcached,couchbase/memcached,couchbase/memcached,owendCB/memcached,daverigby/memcached,couchbase/memcached,owendCB/memcached,mrkwse/memcached,owendCB/memcached,daverigby/memcached,cloudrain21/memcached-1