CMake: No need to update the reader when it already is up to date

The reader notifies us about the configuration being changed, so there
is no need to tell it about those changes again.

Change-Id: I458947babf1cd9c50a66ea7863f37d1e43d6c5f2
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/plugins/cmakeprojectmanager/builddirmanager.cpp

@@ -466,10 +466,8 @@ void BuildDirManager::checkConfiguration()
         box->setDefaultButton(defaultButton);
 
         int ret = box->exec();
-        if (ret == QMessageBox::Apply) {
+        if (ret == QMessageBox::Apply)
             m_buildConfiguration->setCMakeConfiguration(newConfig);
-            updateReaderData(); // Apply changes to reader
-        }
     }
 }