FIX: Simplify schema for ServerBasedAPIAccessControl to optionally accept base_url

the proposed discriminated union was not working and would require the creation of a subschema inside this schema, so for simplicity if base_url is included it takes priority over the server+port defaults

Author: Matheus Luís

bluesky_httpserver/authorization/api_access.py

@@ -461,34 +461,26 @@ def __init__(self, *, roles=None, users=None):
 
 
 _schema_ServerBasedAPIAccessControl = """
-$schema": http://json-schema.org/draft-07/schema#
+$schema": http://json-schema.org/draft-07/schema
 type: object
 additionalProperties: false
 properties:
   instrument:
     type: string
-  roles:  # Detailed validation is performed elsewhere
+  roles:
     description: The value is passed to BasicAPIAccessControl object
-  oneOf:
-    - properties:
-        base_url:
-          type: string
-      required:
-        - base_url
-    - properties:
-        server:
-          type: string
-        port:
-          type: integer
-      required:
-        - server
-        - port
   update_period:
     type: integer
   expiration_period:
     type: [integer, "null"]
   http_timeout:
     type: integer
+  server:
+    type: string
+  port:
+    type: integer
+  base_url:
+    type: [string, "null"]   
 """