fix: Set QApplication class in systray's python script

This is required to be able to configure properly the systray tray applet in KDE Plasma

Fixes #201

src/script/arch-update-tray.py

@@ -104,7 +104,7 @@ def __init__(self, statefile):
         self.watcher = None
 
         # Application
-        app = QApplication([])
+        app = QApplication(["Arch-Update"])
         app.setQuitOnLastWindowClosed(False)
 
         # Icon