Core/Spell: allow damage from binary spells to go through elemental resistance's damage reduction.

src/server/game/Entities/Unit/Unit.cpp

@@ -1603,10 +1603,6 @@ static float GetArmorReduction(float armor, uint8 attackerLevel)
     {
         if (spellInfo->HasAttribute(SPELL_ATTR4_IGNORE_RESISTANCES))
             return 0;
-
-        // Binary spells can't have damage part resisted
-        if (spellInfo->HasAttribute(SPELL_ATTR0_CU_BINARY_SPELL))
-            return 0;
     }
 
     float const averageResist = Unit::CalculateAverageResistReduction(attacker, schoolMask, victim, spellInfo);