slirp: Add Samuel Thibault's staging tree for slirp

Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Acked-by: NThomas Huth <thuth@redhat.com>

MAINTAINERS

@@ -1675,6 +1675,7 @@ S: Maintained
 F: slirp/
 F: net/slirp.c
 F: include/net/slirp.h
+T: git https://people.debian.org/~sthibault/qemu.git slirp
 T: git git://git.kiszka.org/qemu.git queues/slirp
 
 Stubs