bepasty: Don't enable app when setup is rerun

Tests:

- Rerun setup after disabling the app. App is not enabled.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/bepasty/__init__.py

@@ -100,7 +100,9 @@ class BepastyApp(app_module.App):
         """Install and configure the app."""
         super().setup(old_version)
         privileged.setup('freedombox.local')
-        self.enable()
+        if not old_version:
+            self.enable()
+
         if old_version == 1 and not privileged.get_configuration().get(
                 'DEFAULT_PERMISSIONS'):
             # Upgrade to a better default only if user hasn't changed the