### Steps to reproduce

1. Login as a user

2. Go to a work package and add some dates

3. Try to delete the start and end date


### What is the buggy behavior?

The dates are not removed at all

### What is the expected behavior?

Begin of the insertion* **Remove start date:** removesEnd of the insertion Begin of the deletion DeletingEnd of the deletion the Begin of the insertionstart date and duration fields and keeps the end date as unique date.

* **Remove end date:** removes the end date and duration fields and keeps the start date as unique date.

* **Remove duration:** removes the duration and end date and keeps the end date as unique date.


End of the insertion Begin of the deletion dates should remove both of them

End of the deletion **Operating System**

* [ ] Windows
* [ ] Mac OS X
* [x] Mobile iOS
* [x] Mobile Android
* [ ] Linux (please specify distro)
* [ ] Chrome OS
* [ ] Other (please specify)