pylint: enable the import-error check

Check for import errors with pylint to make sure new python package
dependencies are not overlooked.

https://fedorahosted.org/freeipa/ticket/6418

Reviewed-By: Petr Spacek <pspacek@redhat.com>
Reviewed-By: Martin Basti <mbasti@redhat.com>

ipaserver/rpcserver.py

@@ -24,7 +24,6 @@ Also see the `ipalib.rpc` module.
 """
 
 from xml.sax.saxutils import escape
-from six.moves.xmlrpc_client import Fault
 import os
 import datetime
 import json
@@ -36,7 +35,10 @@ import ldap.controls
 from pyasn1.type import univ, namedtype
 from pyasn1.codec.ber import encoder
 import six
+# pylint: disable=import-error
 from six.moves.urllib.parse import parse_qs
+from six.moves.xmlrpc_client import Fault
+# pylint: enable=import-error
 
 from ipalib import plugable, errors
 from ipalib.capabilities import VERSION_WITHOUT_CAPABILITIES