QQuickVTKInteractorAdapter: support Qt 5.9
The used signature is new in Qt 5.12. Since it's such a small change, preserve 5.9 compatibility.
Backport: release
Backport: paraview/release
The used signature is new in Qt 5.12. Since it's such a small change, preserve 5.9 compatibility.
Backport: release
Backport: paraview/release