Update libgsystem

For https://bugzilla.gnome.org/show_bug.cgi?id=711057

diff --git a/src/libgsystem b/src/libgsystem
index aaa4e8623c578a1cf385f615ebd9713b5c18afa0..f861ba48955b6c3a3a05cdadae510695db3b5a99 160000 (submodule)
--- a/src/libgsystem
+++ b/src/libgsystem
@@ -1 +1 @@
-Subproject commit aaa4e8623c578a1cf385f615ebd9713b5c18afa0
+Subproject commit f861ba48955b6c3a3a05cdadae510695db3b5a99