Update core.

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

diff --git a/core b/core
index ca47693..e25ddad 160000 (submodule)
--- a/core
+++ b/core
@@ -1 +1 @@
-Subproject commit ca476935c2eed1151b14a783f2ca404218ebfae4
+Subproject commit e25ddad9784ef9e8e4de1847b50207f88622a165