Update core

Signed-off-by: Florent Bruneau <florent.bruneau@polytechnique.org>

diff --git a/core b/core
index 9d421b2..ca6384f 160000 (submodule)
--- a/core
+++ b/core
@@ -1 +1 @@
-Subproject commit 9d421b2930b5cd1b70dbbe5d11ad3c8c4197faa5
+Subproject commit ca6384fb36992e0899efea20ea1082bfc77d7c41