Core/Scripting: fixed build. Re-enable ModifyVehiclePassengerExitPos for CreatureScript to allow scripted creatures that already have an AI to benefit from its functionality as well

(cherry picked from commit f0485cea39)

src/server/game/Scripting/ScriptMgr.h

@@ -423,6 +423,8 @@ class TC_GAME_API CreatureScript : public ScriptObject
         CreatureScript(char const* name);
 
     public:
+        // Called when an unit exits a vehicle
+        virtual void ModifyVehiclePassengerExitPos(Unit* /*passenger*/, Vehicle* /*vehicle*/, Position& /*pos*/) { }
 
         // Called when a CreatureAI object is needed for the creature.
         virtual CreatureAI* GetAI(Creature* /*creature*/) const = 0;