Fixed crash when attacking while having a bBreakArmorRate item equipped (typo in r13800) (bugreport:3121).

git-svn-id: https://svn.code.sf.net/p/rathena/svn/trunk@13810 54d463be-8e91-2dee-dedb-b68131a5f0ec

src/map/skill.c

@@ -946,7 +946,7 @@ int skill_additional_effect (struct block_list* src, struct block_list *bl, int
 			rate = 0;
 			if( sd )
 				rate += sd->break_armor_rate;
-			if( rate )
+			if( sc && sc->data[SC_MELTDOWN] )
 				rate += sc->data[SC_MELTDOWN]->val3;
 			if( rate )
 				skill_break_equip(bl, EQP_ARMOR, rate, BCT_ENEMY);