FIX(single-gist): fix `gist.owner.login` exception on state change
FIX(single-gist): fix `gist.owner.login` exception on state change

- fix `gist.owner.login` not set/available on gist state change (public/private), causing firing exception.

shmool/Gisto,Gisto/Gisto,shmool/Gisto,Gisto/Gisto,shmool/Gisto,Gisto/Gisto,Gisto/Gisto