[FacebookBridge] Add requester languages to HTTP header
[FacebookBridge] Add requester languages to HTTP header

If no accepted languages are specified Facebook will guess your
language. This guess can go horribly wrong if your server does not
provide origin information.

This adds a context header with language information when retrieving
page contents. The accepted languages are read from the list of
accepted languages specified by the web browser of the requester.

References #530

simonbru/rss-bridge,RSS-Bridge/rss-bridge,sebsauvage/rss-bridge,GregThib/rss-bridge,Frenzie/rss-bridge,ORelio/rss-bridge,kranack/rss-bridge,Frenzie/rss-bridge,teromene/rss-bridge,kranack/rss-bridge,RSS-Bridge/rss-bridge,teromene/rss-bridge,Riduidel/rss-bridge,Riduidel/rss-bridge,ORelio/rss-bridge,kranack/rss-bridge,RSS-Bridge/rss-bridge,kranack/rss-bridge,simonbru/rss-bridge,Riduidel/rss-bridge,LogMANOriginal/rss-bridge,ORelio/rss-bridge,LogMANOriginal/rss-bridge