The default /etc/shells file doesn't have /bin/zsh in it.
After upgrading to 6.1, all user zsh accounts cannot login
to the ftp server because wu-ftpd doesn't think their shell
is allowed. When we added '/bin/zsh' to /etc/shells our
problem disappeared. Maybe the zsh rpm needs to add
/bin/zsh to the /etc/shells file.
Confirmed: Someone forgot to put zsh in /etc/shells.
Rawhide's zsh puts itself in /etc/shells, so this is fixed.