A user did "ceph-backport.sh --setup" and entered the interactive setup routine.
After entering a valid GitHub personal access token, she got the following
message:
ceph-backport.sh: my GitHub username is callithea
ceph-backport.sh: You must provide a valid GitHub personal access token
ceph-backport.sh: ERROR: problem detected in your setup
ceph-backport.sh: Run "ceph-backport.sh --setup" to fix
and the script aborted. This commit fixes the issue.