JavaFX app with all permissions cannot set SecurityManager to null in some cases when run as a Java Web Start application.

Here is the exception from the test case.

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java.lang.SecurityException: JVM Shared, not allowed to set security manager
at sun.plugin2.applet.SecurityManagerHelper.checkPermissionHelper(Unknown Source)
at sun.plugin2.applet.FXAppletSecurityManager.checkPermission(Unknown Source)
at java.lang.System.setSecurityManager0(Unknown Source)
at java.lang.System.setSecurityManager(Unknown Source)
at FXSetSM2NullApp.start(FXSetSM2NullApp.java:24)
at com.sun.javafx.applet.FXApplet2$2.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl$6$1.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl$6$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$6.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$300(Unknown Source)
at com.sun.glass.ui.win.WinApplication$4$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
>>>Test FAILed, cause: java.lang.SecurityException: JVM Shared, not allowed to set security manager
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