Improve error message in ipactl
If a hostname configured in /etc/ipa/default.conf is changed and
is different from the one stored in LDAP in cn=ipa,cn=etc,$SUFFIX
ipactl gives an unintelligible error.
This patch improves the error message and also offers a list of
configured master so that the hostname setting in IPA configuration
can be easily fixed.
https://fedorahosted.org/freeipa/ticket/1558