Fix set_task_push_notification_config integration test

Author: aneeshgarg

src/a2a/server/request_handlers/rest_handler.py

@@ -192,7 +192,7 @@ async def get_push_notification(
         )
 
     @validate(
-        lambda self: self.agent_card.capabilities.pushNotifications,
+        lambda self: self.agent_card.capabilities.push_notifications,
         'Push notifications are not supported by the agent',
     )
     async def set_push_notification(

src/a2a/utils/error_handlers.py

@@ -71,8 +71,8 @@ async def wrapper(*args: Any, **kwargs: Any) -> Response:
             return JSONResponse(
                 content={'message': error.root.message}, status_code=http_code
             )
-        except Exception:
-            logger.log(logging.ERROR, 'Unknown error occurred')
+        except Exception as e:
+            logger.log(logging.ERROR, f'Unknown error occurred {e}')
             return JSONResponse(
                 content={'message': 'unknown exception'}, status_code=500
             )