50fdc80 ipatests: fix bind service name

Authored and Committed by frenaud 3 years ago
    ipatests: fix bind service name
    
    With the commit 721435cf7f2ed41fe807c34022fed31c792b4497
    the service name for bind is now 'named' instead of
    'named-pkcs11' on fedora. The ipa-healthcheck test was hardcoding
    the service name but it should instead use the name stored in
    knownservices.named.systemd_name as it varies depending on
    the OS.
    
    Fixes: https://pagure.io/freeipa/issue/8482
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>