[MemcachedCache] loadData now returns null instead of false (#1592)
[MemcachedCache] loadData now returns null instead of false (#1592)

FileCache and SQLiteCache returns null on cache miss. This is important if using strict comparing (for example when using "===")
ORelio/rss-bridge,kranack/rss-bridge,sebsauvage/rss-bridge,RSS-Bridge/rss-bridge,kranack/rss-bridge,RSS-Bridge/rss-bridge,RSS-Bridge/rss-bridge,Riduidel/rss-bridge,ORelio/rss-bridge,kranack/rss-bridge,kranack/rss-bridge,ORelio/rss-bridge,Riduidel/rss-bridge,Riduidel/rss-bridge