Release date should not be required before the first release

[darkdragon-001]

Release date should be optional

As the help for the field release date says

This key contains the date at which the latest version was released. This date is mandatory if the software has been released at least once and thus the version number is present.

Even when no version number is present, the field is still marked required.

Steps to reproduce

Go to the editor and don't fill in a version number and release date.

Expected behaviour

Should be valid without release date.

Actual behaviour

Validation fails.