Ignore content_default_http_proxy param for SAT-30769

Signed-off-by: Gaurav Talreja <gtalreja@redhat.com>

Author: Gauravtalreja1

nailgun/entities.py

@@ -5563,6 +5563,7 @@ def read(self, entity=None, attrs=None, ignore=None, params=None):
         ignore.add('organization')
         ignore.add('location')
         ignore.add('cacert')
+        ignore.add('content_default_http_proxy')
         return super().read(entity, attrs, ignore, params)