:bug: use null in SimdJSON

diff --git a/plug b/plug
index 22e09191b1d72366e7b1a355818a397eaec2fe79..37a924de17793ffa43e154a6c0dccd295346f190 160000 (submodule)
--- a/plug
+++ b/plug
@@ -1 +1 @@
-Subproject commit 22e09191b1d72366e7b1a355818a397eaec2fe79
+Subproject commit 37a924de17793ffa43e154a6c0dccd295346f190