[FIX] mail: link in livechat
[FIX] mail: link in livechat

When a user sends a link thanks to the livechat, the link is not
clickable is the recipient is on the frontend (e.g. visitor of the
website). On the other hand, a link sent from the frontend to the
backend works.

This is because the message is sent as "html" from the backend,
therefore no link conversion is done during the post-process of the
massege (method `message_post`).

Note that a link sent and received in the backend works because
additional formatting is done (convert emojis, add links...).

opw-686063

Elico-Corp/odoo_OCB,bplancher/odoo,storm-computers/odoo,hip-odoo/odoo,dfang/odoo,dfang/odoo,microcom/odoo,storm-computers/odoo,bplancher/odoo,microcom/odoo,laslabs/odoo,laslabs/odoo,ygol/odoo,storm-computers/odoo,ygol/odoo,dfang/odoo,Elico-Corp/odoo_OCB,ygol/odoo,laslabs/odoo,bplancher/odoo,storm-computers/odoo,bplancher/odoo,bplancher/odoo,Elico-Corp/odoo_OCB,dfang/odoo,dfang/odoo,hip-odoo/odoo,laslabs/odoo,dfang/odoo,hip-odoo/odoo,laslabs/odoo,ygol/odoo,Elico-Corp/odoo_OCB,storm-computers/odoo,microcom/odoo,hip-odoo/odoo,hip-odoo/odoo,laslabs/odoo,storm-computers/odoo,hip-odoo/odoo,Elico-Corp/odoo_OCB,ygol/odoo,microcom/odoo,Elico-Corp/odoo_OCB,bplancher/odoo,ygol/odoo,microcom/odoo,microcom/odoo,ygol/odoo