First step of merging replica installation of both DLs
    
    The installation steps of replica installation on DL0 and
    DL1 don't differ too much and should be merged. When
    host enrollment on DL0 is finished, most of the code will
    be the same.
    
    https://fedorahosted.org/freeipa/ticket/6392
    
    Reviewed-By: Martin Basti <mbasti@redhat.com>
    Reviewed-By: Jan Cholasta <jcholast@redhat.com>