Update core

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

diff --git a/core b/core
index d1bdef7..5f6b3a2 160000 (submodule)
--- a/core
+++ b/core
@@ -1 +1 @@
-Subproject commit d1bdef74354a292f610159205fdb974558c15c3b
+Subproject commit 5f6b3a28efe41c038f349fb0b281d9637f7078de