Qemu VNC keymap

Hi there!

Currently, in all XS version (except Ely), qemu-dm is started with the -k en-us. That's a deprecated way to do it since at least 2009 (check this message from LibVirt guys, saying it's not necessary at the time: https://www.redhat.com/archives/libvir-list/2009-May/msg00234.html )

Hard coding the keyboard causes a lot of problem for non-us layouts, and just removing it won't break anything. In fact, this commit is already fixing that:

https://github.com/xapi-project/xenopsd/commit/0066fbf7ca30082fd97e1dce04f90f1f2994a07a

Would it be possible to backport this change to previous versions of XenServer? (ideally, every one of them )

Thanks!