We were assuming that, if the realm was correct then also the
    rest of the krb5.conf configuration were. This clearly breaks
    with the default EXAMPLE.COM realm configuratrion. Furthermore
    it makes it not possible to try to 'fix' an installation by
    rerruninng ipa-client-install
    
    This patch removes the special case and avoids krb5.conf only
    if the on_master flag is passed.
    Fix also one inner 'if' statement to be simpler to understand.