fix: wrong accept header in mastodonbridge (#3025)
fix: wrong accept header in mastodonbridge (#3025)

Fixes bug introduced by afcc38786e85cfe99efacfddb3a222989bd09f5e because of
the default Accept header which caused xml to be returned.

Fix #3024
RSS-Bridge/rss-bridge,Riduidel/rss-bridge,ORelio/rss-bridge,Riduidel/rss-bridge,ORelio/rss-bridge,ORelio/rss-bridge,RSS-Bridge/rss-bridge,RSS-Bridge/rss-bridge,Riduidel/rss-bridge