server_environment: fix default method not passed

before this commit, default values were not populated
in other environments. The problem was only seen with
data_encryption which save all the values for all the environments.

server_environment/models/server_env_mixin.py

@@ -407,6 +407,7 @@ def _server_env_add_default_field(self, base_field):
                     "sparse": "server_env_defaults",
                     "automatic": True,
                     "string": fieldlabel,
+                    "default": base_field.default,
                 }
             )