Use custom model fields in user model

bookwyrm/activitypub/person.py

@@ -2,9 +2,18 @@
 from dataclasses import dataclass, field
 from typing import Dict
 
-from .base_activity import ActivityObject, PublicKey
+from .base_activity import ActivityObject
 from .image import Image
 
+
+@dataclass(init=False)
+class PublicKey(ActivityObject):
+    ''' public key block '''
+    owner: str
+    publicKeyPem: str
+    type: str = 'PublicKey'
+
+
 @dataclass(init=False)
 class Person(ActivityObject):
     ''' actor activitypub json '''