Improved ResourceListeners

Former-commit-id: 8016c23cb75aab94762a1e2838dbbcac2093119b

src/Nazara/Utility/StaticMesh.cpp

@@ -128,6 +128,4 @@ void NzStaticMesh::OnResourceReleased(const NzResource* resource, int index)
 		m_vertexBuffer = nullptr;
 	else
 		NazaraInternalError("Not listening to " + NzString::Pointer(resource));
-
-	resource->RemoveResourceListener(this);
 }