Remove duplicate log entry for conn alloc failures
Remove duplicate log entry for conn alloc failures

dispatch_new_connections added a "generic" log entry if
conn_new returned nullptr, but conn_new had already
logged the reason why it failed to create the new
connection.

Change-Id: I54bcbfd28c4307f00f407c5fba80fc525281861e
Reviewed-on: http://review.couchbase.org/113629
Tested-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@couchbase.com>
Reviewed-by: Jim Walker <1cd02e31b43620d7c664e038ca42a060d61727b9@couchbase.com>

daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine,daverigby/kv_engine