Another tamedog message

Give a different message when a peaceful creature was tamed.
Allow suppressing this and the previous message, when the caller
handles messaging.

src/trap.c

@@ -4228,7 +4228,7 @@ domagictrap(void)
                         continue;
                     mtmp = m_at(u.ux + i, u.uy + j);
                     if (mtmp)
-                        (void) tamedog(mtmp, (struct obj *) 0);
+                        (void) tamedog(mtmp, (struct obj *) 0, TRUE);
                 }
             break;
         }