A new upstream version has been available and has been for a few months. I have updated the spec file and performed a scratch build in Koji. https://src.fedoraproject.org/rpms/glabels/pull-request/1
This bug appears to have been reported against 'rawhide' during the Fedora 31 development cycle. Changing version to '31'.
Apologies, not sure why this is still open and assigned to me. Kalev Lember fixed this by updating to 3.4.1 back in February. (Thanks, Kalev!) Closing this ticket as CURRENTRELEASE.