[FIX] website_mail_channel: unsubscription

Fixes 27280fefa9e7cad0143aca688149f19ebdb684f6:

* `partner_id` is an `int` not a recordset
* qweb Response is lazy (the template is only looked up and rendered
  when we actually need to send the content over the wire) => the error
  would occur outside of the try..except block. Force rendering
  (`Response.flatten`) so we can handle the issue here
* Uses the HttpCase interface to contact the server over a new socket
  (same as tours & al) because using `werkzeug.test.Client` would not
  use the correct cursor (?) and so the test data would not be visible

0 files changed, 0 insertions, 0 deletions