Fix: wished-for doors in wizmode always vertical

Wishing for a door is intended to retain the existing 'horizontal' value
of the surrounding wall or door (see comment in the wizterrainwish
'door' case).  However, the field was being reset by mistake, causing
all door wishes to create vertical doors.  Preserve it as intended.

src/objnam.c

@@ -3474,10 +3474,10 @@ wizterrainwish(struct _readobjnam_data *d)
             || IS_DOOR(oldtyp) || oldtyp == SDOOR) {
             /* when new terrain is a fountain, 'blessedftn' was explicitly
                set above; likewise for grave and 'disturbed'; when it's a
-               secret door, the old type was a wall or a door and we retain
-               the 'horizontal' value from those */
+               door, the old type was a wall or a door and we retain the
+               'horizontal' value from those */
             if (!IS_FOUNTAIN(lev->typ) && !IS_GRAVE(lev->typ)
-                && lev->typ != SDOOR)
+                && !IS_DOOR(lev->typ) && lev->typ != SDOOR)
                 lev->horizontal = 0; /* also clears blessedftn, disturbed */
         }
         /* note: lev->lit and lev->nondiggable retain their values even