contrib/makerepo.sh: adapt to "fedpkg prep" new behavior
Summary
Fixes the makerepo.sh script when using a newer version of fedpkg.
Purpose
To be able to run makerepo.sh script on environments that uses a newer version of fedpkg.
Checklist
Please read https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/blob/main/CONTRIBUTING.md before opening the merge request. In particular, check that:
-
the subject for all commits is concise and explicative -
the message for all commits explains the reason for the change -
the source is properly formatted -
any relevant documentation is up to date -
you have added unit tests if applicable -
the NEWS file is updated when the change deserves to be mentioned, for example for new features, behavior changes, API deprecations, etc.