Allow blank to email in user-update

User cannot set blank to email address when use "user-update".

This patch fixes this problem.

Change-Id: I3b9494a1c668358a529031c366c55b303f43c533
Closes-bug: #1226439
Change Babel to a runtime requirement

Fixes bug #1226736

Change-Id: Id0ab5a1b74688601f4f8dd1c2613f4cee93401ab
Merge "Allow blank to email in user-update"
Merge "Change Babel to a runtime requirement"