MAINTAINERS: Update 9pfs tree URL

I've already moved my repositories to gitlab for extra CI coverage,
and I won't use the ones at github anymore.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <161071814430.152031.14540382419012818908.stgit@bahia.lan>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
diff --git a/MAINTAINERS b/MAINTAINERS
index 34359a9..fbb228e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1828,7 +1828,7 @@
 F: fsdev/
 F: docs/interop/virtfs-proxy-helper.rst
 F: tests/qtest/virtio-9p-test.c
-T: git https://github.com/gkurz/qemu.git 9p-next
+T: git https://gitlab.com/gkurz/qemu.git 9p-next
 
 virtio-blk
 M: Stefan Hajnoczi <stefanha@redhat.com>