Do not ignore the state of a window when opening it

aqt/__init__.py

@@ -53,7 +53,7 @@ class DialogManager(object):
     def open(self, name, *args):
         (creator, instance) = self._dialogs[name]
         if instance:
-            instance.setWindowState(Qt.WindowActive)
+            instance.setWindowState(instance.windowState() | Qt.WindowActive)
             instance.activateWindow()
             instance.raise_()
             return instance
@@ -253,4 +253,4 @@ environment points to a valid, writable folder.""")
     # load the main window
     import aqt.main
     mw = aqt.main.AnkiQt(app, pm, args)
-    app.exec_()
+    app.exec_()