Minor.

diff --git a/m4 b/m4
index a3d7a33..9763824 160000 (submodule)
--- a/m4
+++ b/m4
@@ -1 +1 @@
-Subproject commit a3d7a3375702caae9794ae3a724e51ae9ee46ac3
+Subproject commit 9763824ebc2240e71a2eff5bb5b3775ab56d0508