Print current level annotation when restoring

Sometimes I annotate a level with a note like "watch out, chameleon
below", which is useful to remind myself of some danger or thing to
remember when returning to the level -- but if saving and restoring on
the level itself there's no reminder of that annotation.  If you restore
on a level with an annotation, print it as part of the "welcome back"
message.

src/allmain.c

@@ -832,6 +832,8 @@ welcome(boolean new_game) /* false => restoring an old game */
         /* if restoring in Gehennom, give same hot/smoky message as when
            first entering it */
         hellish_smoke_mesg();
+        /* remind player of the level annotation, like in goto_level() */
+        print_level_annotation();
     }
 }