Bump to 6.4 for weekly

Change-Id: I41ae00be50941281f8377f53e2de5e3c19358ac9
Signed-off-by: Josue Rivera <prbassplayer@gmail.com>
diff --git a/config/common.mk b/config/common.mk
index 45c5f50..7d92fd3 100644
--- a/config/common.mk
+++ b/config/common.mk
@@ -158,7 +158,7 @@
 # KitKat SlimKat freeze code
 PRODUCT_VERSION_MAJOR = 4.4.4
 PRODUCT_VERSION_MINOR = build
-PRODUCT_VERSION_MAINTENANCE = 6.3
+PRODUCT_VERSION_MAINTENANCE = 6.4
 ifdef SLIM_BUILD_EXTRA
     SLIM_POSTFIX := -$(SLIM_BUILD_EXTRA)
 endif