Add ip6 for host class (#1282) (#1283)

(cherry picked from commit 939498a)

Co-authored-by: Shubham Ganar <67952129+shubhamsg199@users.noreply.github.com>

Author: Satellite-QE

nailgun/entities.py

@@ -4313,6 +4313,7 @@ def __init__(self, server_config=None, **kwargs):
             'interface': entity_fields.OneToManyField(Interface),
             'interfaces_attributes': entity_fields.DictField(),
             'ip': entity_fields.StringField(),
+            'ip6': entity_fields.StringField(),
             'location': entity_fields.OneToOneField(Location, required=True),
             'mac': entity_fields.MACAddressField(),
             'managed': entity_fields.BooleanField(),