These flags were adding redundant configs to the fuzzer.

BUG=angleproject:1522

Change-Id: I49ad56f0d7aceaae326d2d4387c4c750866465f3
Reviewed-on: https://chromium-review.googlesource.com/408338
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>