[omemo] Transfer error is set incorrectly

Versions

• OS: Windows 10
• GTK Version: 3.24.29
• PyGObject Version: 3.40.1
• GLib Version : 2.66.7
• python-nbxmpp Version: 2.0.2
• Gajim Version: 1.3.2

Traceback

Traceback (most recent call last):
  File "C:\Users\iirol\AppData\Roaming\Gajim\Plugins\omemo\file_crypto.py", line 127, in _on_finished
    transfer.set_error('http-error', 'Download failed: %s', transfer.request_uri)
TypeError: set_error() takes from 2 to 3 positional arguments but 4 were given

Steps to reproduce the problem

Send an attachment from Conversations to Gajim. The sending account has a self-signed certificate.