Remove duplicated flags.
Remove duplicated flags.

On CL:2044001 these duplicated flags were added without any mention
of it on the commit message. Anyway, these duplicated flags are
required only once.

TEST=build and unittest
BUG=None

Change-Id: Ic3b6fccc2bdf9e462deebe474b85cb4e3f5cc1b1
Reviewed-on: https://chromium-review.googlesource.com/186383
Reviewed-by: David Zeuthen <28530fef9e2e0b434a729cd52034a7c3086e28c1@chromium.org>
Commit-Queue: Alex Deymo <0bb68aca05e38f8ef6dec21b678bbb2a1f313713@chromium.org>
Tested-by: Alex Deymo <0bb68aca05e38f8ef6dec21b678bbb2a1f313713@chromium.org>

mjg59/update_engine,mjg59/update_engine,endocode/update_engine,endocode/update_engine,endocode/update_engine,mjg59/update_engine