As GUI elements are present in ProgressListModel, use QApplication rather than
QCoreApplication to ensure a GUI eventloop.

Fixes reported issue https://bugs.kde.org/show_bug.cgi?id=348123

--- plasma-workspace-5.4.2.old/kuiserver/main.cpp       2015-10-01 05:56:51.000000000 -0400
+++ plasma-workspace-5.4.2.new/kuiserver/main.cpp       2015-11-02 16:23:27.424833932 -0500
@@ -35,7 +35,7 @@ extern "C" Q_DECL_EXPORT int kdemain(int
 {
     QLoggingCategory::setFilterRules(QStringLiteral("kuiserver.debug = true"));

-    QCoreApplication app(argc, argv);
+    QApplication app(argc, argv);
     app.setApplicationName(QStringLiteral("kuiserver"));
     app.setApplicationVersion(QStringLiteral("2.0"));
     app.setOrganizationDomain(QStringLiteral("kde.org"));