update Maven submodule reference

diff --git a/maven b/maven
index 1f40ae4f2766e4a32dc1e11e7f610bd75da0e986..a4cb7ef844cdd325c359a37b498036388951bc35 160000 (submodule)
--- a/maven
+++ b/maven
@@ -1 +1 @@
-Subproject commit 1f40ae4f2766e4a32dc1e11e7f610bd75da0e986
+Subproject commit a4cb7ef844cdd325c359a37b498036388951bc35