broken large box wording change

> When you try to #force a large box or chest whose lock is already broken from a
> previous #force, the game tells you "There is a broken large box here, but its
> lock is already broken." It's minor, but this implies that the box being broken
> is separate from the lock being broken (as well as that the box itself *can* be
> broken).

change the wording to "lock-damaged box" and suppress
", but its lock is aleady broken" when "lock-damaged box" has
already been displayed.

(Nobody particularly likes the wording "lock-damaged box" either, but at least
it seems less misleading)

src/objnam.c

@@ -998,7 +998,7 @@ unsigned doname_flags;
             /* 3.6.0 used "unlockable" here but that could be misunderstood
                to mean "capable of being unlocked" rather than the intended
                "not capable of being locked" */
-            Strcat(prefix, "broken ");
+            Strcat(prefix, "lock-damaged ");
         else if (obj->olocked)
             Strcat(prefix, "locked ");
         else