swagger: fixed invalid specification (#5485)

Currently, the swagger spec doesn't follow the Swagger 2.0 specification. So, I facing 4 errors when trying generate the Golang client for chatwoot.
Due to the spec, the binary field should use format: binary beside type: string

Signed-off-by: Giau. Tran Minh <hello@giautm.dev>
Co-authored-by: Sojan Jose <sojan@pepalo.com>

swagger/definitions/index.yml

@@ -158,13 +158,6 @@ conversation_status_toggle:
 conversation_labels:
   $ref: ./resource/extension/conversation/labels.yml
 
-## message
-extended_message:
-  allOf:
-    - $ref: '#/definitions/generic_id'
-    - $ref: '#/definitions/message'
-    - $ref: ./resource/extension/message/with_source_sender.yml
-
 
 ## report
 account_summary: