[16.0] hr_expense_invoice: duplicated expense journal entry

[SoniaViciana]

Module

hr_expense_invoice https://github.com/OCA/hr-expense/pull/234

Describe the bug

If i have this expense report:

Journal entries details will be:

So, untaxed amount does not match:

• Journal items = 3.102,60
• Expense report = 1.743,41

To Reproduce

Affected versions: 16

Steps to reproduce the behavior:

1. Make a expense report with 2 lines of expense
2. Create a vendor invoice of one of them and publish
3. "Post Journal Entries" from the expense report

@pedrobaeza