Fix for gestures and multitouch on linux

[Anafinow, Andrej]

Hello,
we have a problem with multitouch and gestures on Linux and JavaFx17.
This is also described here: https://bugs.openjdk.java.net/browse/JDK-8090954
The sample project "GestureEventsExample" at https://docs.oracle.com/javafx/2/events/gestures.htm does not work either.
We looked at the code and fixed the problem.
See our commit at https://github.com/tms-bonn/jfx.
With these changes, the above example works.
The following touch and multi-touch functions were tested: Rotate, Zoom, Scroll and LongPress.
Our current problem was actually about controlling the Openlayers map in a WebView with gestures on a touch monitor.
All the above functions work without any problems.
We would like to ask the community to take a look at our changes and maybe test them
Regards,
Andrej