Change copied bl type to BL_NUL for delayed clif_clearunit (#7640)

Co-authored-by: Lemongrass3110 <lemongrass@kstp.at>

src/map/clif.cpp

@@ -1006,7 +1006,13 @@ static TIMER_FUNC(clif_clearunit_delayed_sub){
 void clif_clearunit_delayed(struct block_list* bl, clr_type type, t_tick tick)
 {
 	struct block_list *tbl = ers_alloc(delay_clearunit_ers, struct block_list);
-	memcpy (tbl, bl, sizeof (struct block_list));
+	tbl->next = nullptr;
+	tbl->prev = nullptr;
+	tbl->id = bl->id;
+	tbl->m = bl->m;
+	tbl->x = bl->x;
+	tbl->y = bl->y;
+	tbl->type = BL_NUL;
 	add_timer(tick, clif_clearunit_delayed_sub, (int)type, (intptr_t)tbl);
 }