Tell apt-ftparchive to not generate  SHA512 hashes.

These clashes with rapture that doesn't generate them.

Change-Id: Id0fed23ffc3ec56646d42fc1fb738e3eb09c3054
diff --git a/update_packages.sh b/update_packages.sh
index 667cd5c..1f3f399 100755
--- a/update_packages.sh
+++ b/update_packages.sh
@@ -16,6 +16,6 @@
 
 (
 	flock -e 200
-	( cd $PRODUCT_OUT/packages; apt-ftparchive packages bsp > Packages )
-	( cd $PRODUCT_OUT/packages; apt-ftparchive packages core >> Packages )
+	( cd $PRODUCT_OUT/packages; apt-ftparchive -o APT::FTPArchive::SHA512=false packages bsp > Packages )
+	( cd $PRODUCT_OUT/packages; apt-ftparchive -o APT::FTPArchive::SHA512=false packages core >> Packages )
 ) 200>$PRODUCT_OUT/obj/packages-lock