Core/Spells: Fix Shadow Bite damage

Closes #591 & #1220 & #1401

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

@@ -10445,6 +10445,10 @@ uint32 Unit::SpellDamageBonus(Unit *pVictim, SpellEntry const *spellProto, uint3
             if (spellProto->SpellFamilyFlags[0] & 0x00004000)
                 if (HasAura(200000))
                     DoneTotalMod *= 4;
+            // Shadow Bite (15% increase from each dot)
+            if (spellProto->SpellFamilyFlags[1] & 0x00400000 && isPet())
+                if (uint8 count = pVictim->GetDoTsByCaster(GetOwnerGUID()))
+                    AddPctN(DoneTotalMod, 15 * count);
         break;
         case SPELLFAMILY_HUNTER:
             // Steady Shot

src/server/game/Spells/SpellEffects.cpp

@@ -543,9 +543,6 @@ void Spell::SpellDamageSchoolDmg(SpellEffIndex effIndex)
                 {
                     if (m_caster->GetTypeId() == TYPEID_UNIT && m_caster->ToCreature()->isPet())
                     {
-                        // Get DoTs on target by owner (5% increase by dot)
-                        damage += int32(CalculatePctN(unitTarget->GetDoTsByCaster(m_caster->GetOwnerGUID()), 5));
-
                         if (Player* owner = m_caster->GetOwner()->ToPlayer())
                         {
                             if (AuraEffect* aurEff = owner->GetAuraEffect(SPELL_AURA_ADD_FLAT_MODIFIER, SPELLFAMILY_WARLOCK, 214, 0))