Core/Spells: Fix hunter pets not losing happiness when dismissed (#30756)

Author: CraftedRO

src/server/game/Spells/SpellEffects.cpp

@@ -1109,7 +1109,7 @@ void Spell::EffectPowerDrain()
         return;
 
     Powers powerType = Powers(effectInfo->MiscValue);
-    if (!unitTarget || !unitTarget->IsAlive() || unitTarget->GetPowerType() != powerType || damage < 0)
+    if (!unitTarget || !unitTarget->IsAlive() || (unitTarget->GetPowerType() != powerType && powerType != POWER_HAPPINESS) || damage < 0)
         return;
 
     Unit* unitCaster = GetUnitCasterForEffectHandlers();