slirp to accept non-local dns server

current version of slirp doesn't allow feeded dns address to be outside of given network.
in many scenarios you need to provide dns server that isn't local.

this simple patch removes checking for if dns server isn't in local subnet.



The feature makes sense and would be acceptable. But please
- post a patch on qemu-devel, following http://wiki.qemu.org/Contribute/SubmitAPatch
- reject non-local DNS servers if restrict=on is selected

Thanks!

ping

[Expired for QEMU because there has been no activity for 60 days.]

A patch has been sent to the list now:
https://lists.gnu.org/archive/html/qemu-devel/2019-10/msg00180.html

Fixed here: https://git.qemu.org/?p=qemu.git;a=commitdiff;h=120b721f5b590393971673
... and released with QEMU v4.2