Make Registry description optional

Currently, parse_registries.py assumes the description property exists
in every registry json it parses. However, according to the spec [1]
it is not a required property, so it may not exist, see [2].
Switch it to optional and use an empty string as a default value.

Testing:
Ran the script and made sure the generated files remain unchanged.

[1] https://redfish.dmtf.org/schemas/v1/MessageRegistry.v1_4_0.json
[2] Run: `curl https://redfish.dmtf.org/schemas/v1/MessageRegistry.v1_4_0.json | jq .definitions.MessageRegistry.required`

Change-Id: I3e9ba84bbdb9ba5e6ed8b00cde48c15a1b5abba6
Signed-off-by: Igor Kanyuka <ifelmail@gmail.com>

Author: ifel

scripts/parse_registries.py

@@ -98,6 +98,7 @@ def update_registries(files: t.List[RegistryInfo]) -> None:
 
             registry.write(REGISTRY_HEADER.format(namespace))
             # Parse the Registry header info
+            description = json_dict.get("Description", "")
             registry.write(
                 "const Header header = {{\n"
                 '    "{json_dict[@Redfish.Copyright]}",\n'
@@ -107,7 +108,7 @@ def update_registries(files: t.List[RegistryInfo]) -> None:
                 "    {version_split[2]},\n"
                 '    "{json_dict[Name]}",\n'
                 '    "{json_dict[Language]}",\n'
-                '    "{json_dict[Description]}",\n'
+                '    "{description}",\n'
                 '    "{json_dict[RegistryPrefix]}",\n'
                 '    "{json_dict[OwningEntity]}",\n'
                 "}};\n"
@@ -119,6 +120,7 @@ def update_registries(files: t.List[RegistryInfo]) -> None:
                     json_dict=json_dict,
                     url=url,
                     version_split=version_split,
+                    description=description,
                 )
             )