Replace "waffles" with the more-specific "waffles@chromium.org"

The presubmit tools choke if they need to process
//ios/chrome/browser/unzip/OWNERS because "waffles" isn't in one of the
expected formats.

NOPRESUBMIT=true

Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I3dce39094d169418253dad154c0eb006201687b0
Reviewed-on: https://chromium-review.googlesource.com/955700
Commit-Queue: Colin Blundell <blundell@chromium.org>
Reviewed-by: Joshua Pawlicki <waffles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543648}

ios/chrome/browser/unzip/OWNERS

-waffles
+waffles@chromium.org