QtSupport: Replace 0 with nullptr

... and let clang-format clean up the indentation.

Change-Id: I56401804899628813e54c5b573806ab149885e67
Reviewed-by: hjk <hjk@qt.io>

src/plugins/qtsupport/qtoptionspage.cpp

@@ -619,7 +619,7 @@ void QtOptionsPageWidget::editPath()
                                      tr("Select a qmake Executable"),
                                      dir,
                                      BuildableHelperLibrary::filterForQmakeFileDialog(),
-                                             0,
+                                     nullptr,
                                      QFileDialog::DontResolveSymlinks));
     if (qtVersion.isEmpty())
         return;