rpmdefines changes depending on rpkg
'rpmdefines' structure needs a different format after it was changed
in rpkg (RHELCMP-9241).
Also fixes some bandit security findings.
Relates: https://pagure.io/rpkg/pull-request/620
JIRA: RHELCMP-9646
Signed-off-by: Ondrej Nosek <onosek@redhat.com>