Memcached crashed when running cbcollect_info

Test itself passed smoothly, however cbcollect_info that we run on every node after test encountered failure:

"Control connection to memcached on 'ns_1@172.23.96.11' disconnected: badmatch, {error, timeout, [

{mc_client_binary, cmd_vocal_recv, 5}

,

{mc_client_binary, select_bucket, 2}

,

{ns_memcached, ensure_bucket, 2}

,

{ns_memcached, handle_info, 2}

,

{gen_server, handle_msg, 5}

,

{ns_memcached, init, 1}

,

{gen_server, init_it, 6}

,

{proc_lib, init_p_do_apply, 3}

]}"