test: use TLS based RHEL repo

molecule/resources/playbooks/prepare.yml

@@ -41,7 +41,7 @@
               gpgkey: "https://dl.fedoraproject.org/pub/epel/RPM-GPG-KEY-EPEL-{{ ansible_distribution_major_version }}"
             - name: "slub"
               description: SLUB YUM repo
-              baseurl: "http://sdvrhelrepo.slub-dresden.de/"
+              baseurl: "https://sdvrhelrepo.slub-dresden.de/"
               gpgcheck: "false"
           become: true
         - name: remove legacy repo configuration to avoid double configuration for SLUB repo