Added missing status_calc_npc for unitwalk script command (required for npc) (#6256)

Thanks to @aleos89

src/map/script.cpp

@@ -18944,6 +18944,13 @@ BUILDIN_FUNC(unitwalk)
 
 	ud = unit_bl2ud(bl);
 
+	if (bl->type == BL_NPC) {
+		if (!((TBL_NPC*)bl)->status.hp)
+			status_calc_npc(((TBL_NPC*)bl), SCO_FIRST);
+		else
+			status_calc_npc(((TBL_NPC*)bl), SCO_NONE);
+	}
+
 	if (!strcmp(cmd,"unitwalk")) {
 		int x = script_getnum(st,3);
 		int y = script_getnum(st,4);