Add cacert to .fields in HttpProxy (#923) (#924)

* Add cacert to .fields in HttpProxy

* ignore cacert in http-proxy.read()

(cherry picked from commit 9d5b535)

Co-authored-by: David Moore <109112035+damoore044@users.noreply.github.com>

nailgun/entities.py

@@ -5005,6 +5005,7 @@ def __init__(self, server_config=None, **kwargs):
             'password': entity_fields.StringField(),
             'organization': entity_fields.OneToManyField(Organization),
             'location': entity_fields.OneToManyField(Location),
+            'cacert': entity_fields.StringField(),
         }
         self._meta = {'api_path': 'api/v2/http_proxies'}
         super().__init__(server_config, **kwargs)
@@ -5030,6 +5031,7 @@ def read(self, entity=None, attrs=None, ignore=None, params=None):
         ignore.add('password')
         ignore.add('organization')
         ignore.add('location')
+        ignore.add('cacert')
         return super().read(entity, attrs, ignore, params)