- ensure that gpg key for opensuse repo is present
 - pre-fill cache with specific node to faster bootstrap in re6stnet-upgrader
 - re6stnet-upgrader doesn't fail if previous version of package was also a re6st-node
 - repositories keys have to be installed before updating package cache
 - re6stnet-upgrader ensures that service is enabled
 - only update once package cache in re6stnet-upgrader