Change in time log causes error because of selected account not being used

[Jordi Casas]

Steps to reproduce:

1.Create a time log on a task
2.Edit this time log and change something, i.e the worked time
3.Click on save/update

Expected result: the changes are saved
Current result: there's an error "Work atribute 'Account' (_Account_) is required" but it is already selected.

Workaround: You have to select again the account from the dropdown and save/update again