[FIX] website_forum: missing parenthesis for function

before this commit, on clicking on Go To Website
smart button in forum is not redirecting to the
corresponding forum due to missing parenthesis
to the function.

after this commit, on clicking the Go To Website
smart button, user is redirected to the forum.

introduced in: https://github.com/odoo/odoo/commit/36c734ab37fdf1d6a245e0e29cfefe3cc46c6d92

closes odoo/odoo#122108

X-original-commit: 6ab323a0eeafe7511db8dd893d8f398544ee08c2
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>

addons/website_forum/models/forum_forum.py

@@ -262,7 +262,7 @@ class Forum(models.Model):
 
     def go_to_website(self):
         self.ensure_one()
-        website_url = self._compute_website_url
+        website_url = self._compute_website_url()
         if not website_url:
             return False
         return self.env['website'].get_client_action(self._compute_website_url())