Update to the latest common-packer

Common-packer is not currently versioned. Update to latest head

Change-Id: I3eb811e71242aee7db31c41fd684bd3d47ef9f66
Signed-off-by: Andrew Grimberg <agrimberg@linuxfoundation.org>

diff --git a/packer/common-packer b/packer/common-packer
index 49b8bab..6961de6 160000 (submodule)
--- a/packer/common-packer
+++ b/packer/common-packer
@@ -1 +1 @@
-Subproject commit 49b8babff7bc2b1bdbd7ae56e61d3eac73f23165
+Subproject commit 6961de60eb1b20375b7b6839f05bff9deed6f621