Fix group content not being updated after addition
Fix group content not being updated after addition

Subscribing to a feed inside a group folder did not give the expected
visual feedback.
Follow-up of #1445
josh64x2/vienna-rss,josh64x2/vienna-rss,josh64x2/vienna-rss,ViennaRSS/vienna-rss,josh64x2/vienna-rss,ViennaRSS/vienna-rss,ViennaRSS/vienna-rss,ViennaRSS/vienna-rss,ViennaRSS/vienna-rss,josh64x2/vienna-rss