Fix gPodder sync timeout: don't refresh feeds on subscription import

With 400 subscriptions, the initial sync POST was triggering 400
sequential RSS fetches in one request, causing a timeout/sync failure.
Feed metadata is populated by the cron job instead.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

gpodder/views.py

@@ -154,15 +154,10 @@ def subscriptions_by_device(request, username, deviceid):
         for url in body.get('add', []):
             if not url:
                 continue
-            feed, created = PodcastFeed.objects.get_or_create(
+            PodcastFeed.objects.get_or_create(
                 user=request.user, rss_url=url,
                 defaults={'title': url}
             )
-            if created:
-                try:
-                    _refresh_feed(feed)
-                except Exception:
-                    pass
             GpodderSubscriptionChange.objects.create(user=request.user, url=url, action='add')
 
         for url in body.get('remove', []):