add protocol violation when we should have gotten an opername, but did not

diff -r 495100bee360 ircd/s_user.c
--- a/ircd/s_user.c
+++ b/ircd/s_user.c
@@ -1293,6 +1293,9 @@
                 }
               }
             }
+            /* no opername? */
+            else
+              protocol_violation(cptr, "Received mode +o for user %s without opername", cli_name(sptr));
           }
         } else {
           ClrFlag(sptr, FLAG_OPER);