Correct defense value used for crushing.

Consider actual defense skill of victim, not the base skill of that
level
Unless the defense skill is higher then base skill for that level, then
use base skill for that level

src/game/Unit.cpp

@@ -2815,11 +2815,13 @@ MeleeHitOutcome Unit::RollMeleeOutcomeAgainst(const Unit* pVictim, WeaponAttackT
         return MELEE_HIT_CRIT;
     }
 
+    tmp = (victimDefenseSkill < victimMaxSkillValueForLevel) ? victimDefenseSkill : victimMaxSkillValueForLevel;
+
     // mobs can score crushing blows if they're 4 or more levels above victim
     // having defense above your maximum (from items, talents etc.) has no effect
     // mob's level * 5 - player's current defense skill - add 2% chance per lacking skill point, min. is 20%
     if ((getLevel() - 4) >= pVictim->getLevel() && !IsNonMeleeSpellCasted(false) /* It should have been !spellCasted but wrath doesn't have that? */
-        && roll < (tmp = (((attackerMaxSkillValueForLevel - victimMaxSkillValueForLevel) * 200) - 2000)))
+        && roll < (tmp = (((attackerMaxSkillValueForLevel - tmp) * 200) - 2000)))
     {
         uint32 typeId = GetTypeId();
         /* It should have been !(((Creature*)this)->GetCreatureInfo()->ExtraFlags & CREATURE_EXTRA_FLAG_NO_CRUSH) but wrath doesn't have that? */