[FIX] website: handle 404 publisher only for notFound exception

Before this commit we cehck first if user was publisher before to check if the
exception was a 404 NotFound.

What's means that we make this check (1 query sql) most of the time for no
reason, and worst case, when the exception crashes the cursor, this check will
reraise a new exception because isPublisher check is done with a closed cursor.

closes odoo/odoo#55789

X-original-commit: 8afa25a9ca3b165033ab664ce3185c453fb2dd85
Signed-off-by: Jérémy Kersten (jke) <jke@openerp.com>