Correct self attribute in ATOM feeds
Correct self attribute in ATOM feeds

Fix for
https://github.com/friendica/friendica/issues/6128#issuecomment-439016471
Special case for DFRN to reduce the risk of unintended side effects

friendica/friendica,friendica/friendica,annando/friendica,friendica/friendica,tobiasd/friendica,fabrixxm/friendica,tobiasd/friendica,fabrixxm/friendica,fabrixxm/friendica,fabrixxm/friendica,tobiasd/friendica,fabrixxm/friendica,friendica/friendica,tobiasd/friendica,annando/friendica,annando/friendica,annando/friendica,tobiasd/friendica,annando/friendica,friendica/friendica