[FIX] sale: rounded sales team invoiced gauge

The price_total field of the account invoice report is not rounded (it cannot be easily rounded, as this has to be done in the sql view)
In a multi currencies environment, this is possible that the price_total value has a lot of digits
We therefore round it manually, for the gauge of the sales team kanban view
Merge branch '8.0' of https://github.com/odoo/odoo into 8.0-linux64