Fixes API search causing 500 error

bookwyrm/connectors/abstract_connector.py

@@ -1,6 +1,6 @@
 ''' functionality outline for a book data connector '''
 from abc import ABC, abstractmethod
-from dataclasses import dataclass
+from dataclasses import asdict, dataclass
 import logging
 from urllib3.exceptions import RequestError
 
@@ -241,6 +241,12 @@ class SearchResult:
         return "<SearchResult key={!r} title={!r} author={!r}>".format(
             self.key, self.title, self.author)
 
+    def json(self):
+        ''' serialize a connector for json response '''
+        serialized = asdict(self)
+        del serialized['connector']
+        return serialized
+
 
 class Mapping:
     ''' associate a local database field with a field in an external dataset '''