fix css minification (double slash in image base64)
fix css minification (double slash in image base64)

zhangzuoqiang/commafeed,ahmadassaf/CommaFeed-RSS-Reader,ahmadassaf/CommaFeed-RSS-Reader,wesley1001/commafeed,tlvince/commafeed,RavenB/commafeed,wesley1001/commafeed,syshk/commafeed,Athou/commafeed,tlvince/commafeed,ebraminio/commafeed,Athou/commafeed,wesley1001/commafeed,syshk/commafeed,zhangzuoqiang/commafeed,Hubcapp/commafeed,zhangzuoqiang/commafeed,wesley1001/commafeed,ahmadassaf/CommaFeed-RSS-Reader,RavenB/commafeed,syshk/commafeed,tlvince/commafeed,ebraminio/commafeed,ahmadassaf/CommaFeed-RSS-Reader,RavenB/commafeed,syshk/commafeed,Hubcapp/commafeed,RavenB/commafeed,zhangzuoqiang/commafeed,Hubcapp/commafeed,tlvince/commafeed,Athou/commafeed,Athou/commafeed,Hubcapp/commafeed,ebraminio/commafeed,ebraminio/commafeed