<AWT Dev> RFR: 8252349 Delete the "sun.awt.X11.checkSTRUT" property

[Sergey Bylokhov]

Hello.
Please review the fix for jdk/client.

Bug: https://bugs.openjdk.java.net/browse/JDK-8252349
Fix: http://cr.openjdk.java.net/~serb/8252349/webrev.00

This property was added to the XToolkit as a workaround for the possible
bugs caused by the JDK-8170937:
https://mail.openjdk.java.net/pipermail/awt-dev/2018-September/014294.html

Since then no bugs were reported, I would like to remove this code.

Also this is one of the places where we have a condition that the Xinerama
is running, and I try to eliminate it step by step.

-- 
Best regards, Sergey.