"artifacts" field is no longer patterned on the "repository" field

[rfay]

After

• Refactor computeLink function and event listeners, fixes #30 #32

went in (thanks @shaal )

the "git repository with artifacts" field in the form is no longer based on the "git repository" field, so it's really easy to push the button without having manually edited the whole artifacts field.

Would appreciate a follow-up to make it be based on the git repository field while that is being edited, as it used to work.

Other options are fine if you see something better.