[RssBridge] Rename PATH_VENDOR to PATH_LIB_VENDOR
[RssBridge] Rename PATH_VENDOR to PATH_LIB_VENDOR

This improves clarity for the parameters

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