Update prezto

diff --git a/prezto b/prezto
index 4b8ef6562077ddc108d65b3ea2252ee39b1667cc..6606cc66f3713b8fafe2265e60cc132dab1f8763 160000 (submodule)
--- a/prezto
+++ b/prezto
@@ -1 +1 @@
-Subproject commit 4b8ef6562077ddc108d65b3ea2252ee39b1667cc
+Subproject commit 6606cc66f3713b8fafe2265e60cc132dab1f8763