[REG 5.10.0 -> 5.10.1] No mouse interaction with Qt Quick based UIs

1. Open a QML file in Creator's Design mode.
2. Select an item.
3. Try to change the item using the Properties editor.
   It doesn't react to mouse clicks.

1. Record some data into Creator's QML profiler.
2. Try to interact with the Timeline view or the Flamegraph view.
   They don't react to mouse clicks.

I used both with installed binaries built on Qt 5.10.0 and they still work well with my own build on Qt 5.10.0. It also seem unlikely that both plugins broke at the same time, so this seems like a regression in Qt 5.10.1.