Corrects Power Swing and Axe Boomerang behavior (#5123)

* Fixes #5109.
* Power Swing should only cast Axe Boomerang when an axe is equipped.
Thanks to @Haydrich!

src/map/skill.cpp

@@ -1765,8 +1765,9 @@ int skill_additional_effect(struct block_list* src, struct block_list *bl, uint1
 		break;
 	case NC_POWERSWING:
 		sc_start(src,bl, SC_STUN, 10, skill_lv, skill_get_time(skill_id, skill_lv));
-		if( rnd()%100 < 5*skill_lv )
-			skill_castend_damage_id(src, bl, NC_AXEBOOMERANG, ((sd) ? pc_checkskill(sd, NC_AXEBOOMERANG) : skill_get_max(NC_AXEBOOMERANG)), tick, 1);
+		skill = pc_checkskill(sd, NC_AXEBOOMERANG);
+		if (sd && skill > 0 && (sd->status.weapon == W_1HAXE || sd->status.weapon == W_2HAXE) && rnd() % 100 < 5 * skill_lv)
+			skill_castend_damage_id(src, bl, NC_AXEBOOMERANG, skill, tick, 1);
 		break;
 	case GC_WEAPONCRUSH:
 		skill_castend_nodamage_id(src,bl,skill_id,skill_lv,tick,BCT_ENEMY);