more #819 - magic harp

The log message for commit 231bd75b7f
said that magic harp was changed to behave the same as scroll/spell
of taming, but the scroll and spell pacify an angry shopkeeper even
if the shk resists.  Change magic harp to do likewise.

src/music.c

@@ -205,7 +205,10 @@ charm_monsters(int distance)
             continue;
 
         if (distu(mtmp->mx, mtmp->my) <= distance) {
-            if (!resist(mtmp, TOOL_CLASS, 0, NOTELL))
+            /* a shopkeeper can't be tamed but tamedog() pacifies an angry
+               one; do that even if mtmp resists in order to behave the same
+               as a non-cursed scroll of taming or spell of charm monster */
+            if (!resist(mtmp, TOOL_CLASS, 0, NOTELL) || mtmp->isshk)
                 (void) tamedog(mtmp, (struct obj *) 0);
         }
     }