Fix UpdateDamagePhysical attack power calculation

It seems to have used old system without unit mods

(based on cmangos/mangos-wotlk@608585935)

Signed-off-by: Xfurry <xfurry.cmangos@outlook.com>

src/game/Entities/StatSystem.cpp

@@ -850,9 +850,8 @@ void Creature::UpdateDamagePhysical(WeaponAttackType attType)
 
     UnitMods unitMod = (attType == BASE_ATTACK ? UNIT_MOD_DAMAGE_MAINHAND : UNIT_MOD_DAMAGE_OFFHAND);
 
-    /* difference in AP between current attack power and base value from DB */
-    float att_pwr_change = GetTotalAttackPowerValue(attType) - GetCreatureInfo()->MeleeAttackPower;
-    float base_value  = GetModifierValue(unitMod, BASE_VALUE) + (att_pwr_change * GetAPMultiplier(attType, false) / 14.0f);
+    float att_pwr = (GetModifierValue(UNIT_MOD_ATTACK_POWER, BASE_VALUE) * GetModifierValue(UNIT_MOD_ATTACK_POWER, BASE_PCT) + GetModifierValue(UNIT_MOD_ATTACK_POWER, TOTAL_VALUE)) * GetModifierValue(UNIT_MOD_ATTACK_POWER, TOTAL_PCT);
+    float base_value  = GetModifierValue(unitMod, BASE_VALUE) + (att_pwr * GetAPMultiplier(attType, false) / 14.0f);
     float base_pct    = GetModifierValue(unitMod, BASE_PCT);
     float total_value = GetModifierValue(unitMod, TOTAL_VALUE);
     float total_pct   = GetModifierValue(unitMod, TOTAL_PCT);