hack to Xquartz to prevent xmodmap from wiping out our valid modmap, per daniels

(cherry picked from commit cab54466a6)

hw/xquartz/darwinKeyboard.c

@@ -795,6 +795,7 @@ void DarwinKeyboardInit(DeviceIntPtr pDev) {
     assert( InitKeyboardDeviceStruct( (DevicePtr)pDev, &keySyms,
                                       keyInfo.modMap, QuartzBell,
                                       DarwinChangeKeyboardControl ));
+    SwitchCoreKeyboard(pDev);
 }