Fixed a bug about shaders in the new Renderer class

git-svn-id: https://sfml.svn.sourceforge.net/svnroot/sfml/branches/sfml2@1365 4e206d99-4929-0410-ac5d-dfc041789085

src/SFML/Graphics/Renderer.cpp

@@ -300,7 +300,7 @@ void Renderer::SetShader(const Shader* shader)
 
         // Store it
         myShader = shader;
-        myShaderIsValid = false;
+        myShaderIsValid = true;
     }
 }