Description of problem: "The ipa-dns-install command failed, exception:
ValueError:" when DNS service is running on different machine and the command
is executed.

Version-Release number of selected component (if applicable):
ipa-server-dns-4.4.0-1.el7.noarch
ipa-server-4.4.0-1.el7.x86_64

How reproducible: Always

Steps to Reproduce:

1. DNS for IPA domain is setup on remote windows machine.
2. Ensure /etc/resolv.conf of IPA server points to windows machine.
3. Install IPA server without integrated DNS.
4. Now run ipa-dns-install command
5. Check the message displayed on the console.

Actual results:
The log file for this installation can be found in
/var/log/ipaserver-install.log
Checking DNS domain testrelm.test., please wait ...
Unexpected error - see /var/log/ipaserver-install.log for details:
ValueError: DNS zone testrelm.test. already exists in DNS and is handled by
server(s): apache.pne.qe.

===/var/log/ipaserver-install.log===
2016-07-08T11:24:41Z DEBUG raw: dns_is_enabled(version=u'2.210')
2016-07-08T11:24:41Z DEBUG dns_is_enabled(version=u'2.210')
2016-07-08T11:24:41Z DEBUG retrieving schema for SchemaCache
url=ldapi://%2fvar%2frun%2fslapd-TESTRELM-TEST.socket
conn=<ldap.ldapobject.SimpleLDAPObject instance at 0x6173cf8>
2016-07-08T11:24:41Z INFO Checking DNS domain testrelm.test., please wait ...
2016-07-08T11:24:41Z DEBUG   File
"/usr/lib/python2.7/site-packages/ipaserver/install/installutils.py", line 752,
in run_script
    return_value = main_function()
File "/usr/sbin/ipa-dns-install", line 148, in main
dns_installer.install_check(True, api, False, options, hostname=api.env.host)
File "/usr/lib/python2.7/site-packages/ipaserver/install/dns.py", line 128, in
install_check
raise e
2016-07-08T11:24:41Z DEBUG The ipa-dns-install command failed, exception:
ValueError: DNS zone testrelm.test. already exists in DNS and is handled by
server(s): apache.pne.qe.

Expected results:
Instead of throwing value error on the console, proper message should be
displayed on the console e.g

ipa-dns-install command failed: DNS zone testrelm.test. already exists in DNS
and is handled by server(s): apache.pne.qe.

Additional info: