[FIX] im_livechat: prefix avatar's src with server url
[FIX] im_livechat: prefix avatar's src with server url

This is required if the livechat is embedded in an external page,
so that it can correctly retrieve the images.

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