[FIX] website_slides: allow portal users to udpate their review

Followup of 86c80d341846894c435b1c8f61ef946b06e72ec7 : currently portal users face an access issue
if they change attachments in their review. This commit fixes that by sudo-ing
access to the attachment as other access is already granted.

Task ID 2214795

closes odoo/odoo#50815

X-original-commit: 90152abef30e043d36f8a8aabfe18c46e807973f
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

addons/website_slides/controllers/mail.py

@@ -29,7 +29,7 @@ class SlidesPortalChatter(PortalChatter):
         '/mail/chatter_update',
         ], type='http', auth="user")
     def mail_update_message(self, res_model, res_id, message, message_id, redirect=None, attachment_ids='', attachment_tokens='', **post):
-        # keep this mecanism intern to slide currently (saas 12.5) as it is
+        # keep this mechanism intern to slide currently (saas 12.5) as it is
         # considered experimental
         if res_model != 'slide.channel':
             raise Forbidden()
@@ -57,7 +57,7 @@ class SlidesPortalChatter(PortalChatter):
         message = request.env['mail.message'].search(domain, limit=1)
         if not message:
             raise NotFound()
-        message.write({
+        message.sudo().write({
             'body': message_body,
             'attachment_ids': [(4, aid) for aid in attachment_ids],
         })