Doc: update QFileDialog::setSideBarUrls code snippet

The example code uses QDesktopServices::storageLocation which has been
replaced by QStandardPaths. This patch fixes this.

Change-Id: Ifff25fcb9d85b37ef8247cb4cd9c4c1c8d368780
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>

src/widgets/doc/snippets/filedialogurls.cpp

@@ -46,8 +46,8 @@ int main(int argv, char **args)
 
 //![0]
     QList<QUrl> urls;
-    urls << QUrl::fromLocalFile("/home/gvatteka/dev/qt-45")
-         << QUrl::fromLocalFile(QDesktopServices::storageLocation(QDesktopServices::MusicLocation));
+    urls << QUrl::fromLocalFile("/Users/foo/Code/qt5")
+         << QUrl::fromLocalFile(QStandardPaths::standardLocations(QStandardPaths::MusicLocation).first());
 
     QFileDialog dialog;
     dialog.setSidebarUrls(urls);