Set a proper desktop file name to fix an icon under Wayland.

src/main.cpp

@@ -65,6 +65,7 @@ int main(int argc, char *argv[])
     QApplication app(argc, argv);
     app.setApplicationName(QStringLiteral("kdenlive"));
     app.setOrganizationDomain(QStringLiteral("kde.org"));
+    app.setDesktopFileName(QStringLiteral("org.kde.kdenlive"));
     app.setWindowIcon(QIcon(QStringLiteral(":/pics/kdenlive.png")));
     KLocalizedString::setApplicationDomain("kdenlive");
     KSharedConfigPtr config = KSharedConfig::openConfig();