autoconf: update to latest for fix of M4 detection.

[bison.git] / submodules / autoconf

diff --git a/submodules/autoconf b/submodules/autoconf
index 936160f7619cb7fddbc424bb5cb9a2f997d8e166..81074eaa201a289d11b6be05e0c78afbe5ff79f5 160000 (submodule)
--- a/submodules/autoconf
+++ b/submodules/autoconf
@@ -1 +1 @@
-Subproject commit 936160f7619cb7fddbc424bb5cb9a2f997d8e166
+Subproject commit 81074eaa201a289d11b6be05e0c78afbe5ff79f5