Core/Player: Fix sight range

Closes issue 4772

--HG--
branch : trunk

src/server/game/Entities/Object/Object.cpp

@@ -1643,7 +1643,7 @@ float WorldObject::GetSightRange(const WorldObject* target) const
     {
         if (ToPlayer())
         {
-            if (target && target->isActiveObject())
+            if (target && target->isActiveObject() && !target->ToPlayer())
                 return MAX_VISIBILITY_DISTANCE;
             else
                 return GetMap()->GetVisibilityRange();