correctly check if ga is defined
correctly check if ga is defined

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