Core/Aura: Replace assert with logged error for invalid AuraRemoveMode

Fix AuraScript::Remove() triggering an assert with default parameter and log an error when Aura is removed with invalid mode AURA_REMOVE_NONE instead of triggering an assert deep down in the call tree.
Fix https://github.com/TrinityCore/TrinityCore/issues/714 , triggered by spell 50240 "Evasive Maneuvers" script

src/server/game/Spells/SpellScript.cpp

@@ -1001,9 +1001,9 @@ DynamicObject* AuraScript::GetDynobjOwner() const
     return m_aura->GetDynobjOwner();
 }
 
-void AuraScript::Remove(uint32 removeMode)
+void AuraScript::Remove(AuraRemoveMode removeMode)
 {
-    m_aura->Remove((AuraRemoveMode)removeMode);
+    m_aura->Remove(removeMode);
 }
 
 Aura* AuraScript::GetAura() const