[FIX] account: explicitely refreshed invoice browse_record(...) in order...

... to have correct 'date' in account.move. (Maintenance Case: 611210)

Steps to reproduce(with timezone Europe/Brussels (+0200)):
1) Create an invoice, say at 1:00 AM of 8 Aug(1:00 AM is needed as the UTC time will be 11:00 PM of 7th Aug),
2) Validating the invoice will set the Invoice date in local time(8th Aug) and the related journal entry will have date in UTC(7th Aug).
The journal entry is expected to have the same 'date' as it's related invoice's date.

This branch fixes this issue this issue, kindly review it.