[FIX] im_livechat: performance issue with _compute_nbr_channel
[FIX] im_livechat: performance issue with _compute_nbr_channel

filtered(lambda c: c.channel_message_ids)
take more than 2 minutes to get executed with a regular user
due to access_right check for every single message.

Solution:
use the previous read_group with the domain channel_message_ids != False
which is equivalent

closes odoo/odoo#54316

X-original-commit: b4dcfc3e273c40c53cbf778152cf38fabb39a096
Signed-off-by: Thibault Delavallee (tde) <2d325771bb6e8870d87f0f3f7b45589a8338e550@openerp.com>

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo