Don't log twice for unauthorized operation

Mon Feb 11 20:32:34.682 [conn9] assertion 16550 not authorized for query on foo.system.namespaces ns:foo.system.namespaces query:{}

Mon Feb 11 20:32:34.682 [conn9] problem detected during query over foo.system.namespaces : { $err: "not authorized for query on foo.system.namespaces", code: 16550 }