Use correct version of core-account

Signed-off-by: Raphaël Barrois <raphael.barrois@polytechnique.org>

diff --git a/core b/core
index 9a12252..24bb393 160000 (submodule)
--- a/core
+++ b/core
@@ -1 +1 @@
-Subproject commit 9a122520bc4c6547f6506a0cd35e49737809b1c4
+Subproject commit 24bb393609c4e87e8578ddaca906c32d99a299bf