cainstall: add dm_password to CA installation
    
    Installation of Certificate Server replica requires directory manager
    password. Specify it explicitly in function call and pass it in
    through an argument.
    
    https://fedorahosted.org/freeipa/ticket/6461
    
    Reviewed-By: Martin Basti <mbasti@redhat.com>
    Reviewed-By: Jan Cholasta <jcholast@redhat.com>