[REG 3.3 -> 3.4] Items in "Locals and Expressions" don't expand at first click

1. Create a new Qt Quick UI project using component set "Qt Quick 2.3".
2. Start debugging this.
   You'll see the "Locals and Expressions" view which displays the items.
3. Double-click the name of of the first item or click the arrow icon.
   Nothing obvious will happen.
4. Double-click the name of of the first item again or click the arrow icon again.
   The item's sub-tree will open.

Double clicking an item should open its sub-tree at the first time. This used to work correctly in Creator 3.3.

Found by Squish test tst_qml_js_console.