updated Maven submodule repository to 1.6.4

diff --git a/maven b/maven
index eea4aebbfe52ec269c54fe20345052fbebd7e090..4b93a1ee457759a023795a518b8b8917aaa8c2e5 160000 (submodule)
--- a/maven
+++ b/maven
@@ -1 +1 @@
-Subproject commit eea4aebbfe52ec269c54fe20345052fbebd7e090
+Subproject commit 4b93a1ee457759a023795a518b8b8917aaa8c2e5