Issue boards add issue button enabled with no lists

When the default welcome list is visible, the add issues button is enabled which causes a JS error when clicked.

assigned to @iamphill

Thanks @iamphill for catching this.

mentioned in commit 2bd1a229

mentioned in merge request !9100 (merged)

closed via merge request !9100 (merged)

mentioned in commit 97ea49c6

added Category:Team Planning label