Revert of Enable -Wunused-lambda-capture warning (patchset #1 id:1 of https://codereview.webrtc.org/2999403002/ )

Reason for revert:
Breaks iOS framework builder.

Original issue's description:
> Enable -Wunused-lambda-capture warning
>
> This should prevent some build errors downstream.
> The warning is currrently disabled in Chromium:
> https://cs.chromium.org/chromium/src/build/config/compiler/BUILD.gn?rcl=735aa36217a394455f70aad87e2c844053fd810a&l=1214
> (see https://crbug.com/681136 for more info).
>
> BUG=webrtc:7133
> NOTRY=True
>
> Review-Url: https://codereview.webrtc.org/2999403002
> Cr-Commit-Position: refs/heads/master@{#19466}
> Committed: https://chromium.googlesource.com/external/webrtc/+/fd7cffa43366d5fb8a95da71fffa7f872037fefe

TBR=charujain@webrtc.org,charujain@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7133

Review-Url: https://codereview.webrtc.org/3007483002
Cr-Original-Commit-Position: refs/heads/master@{#19473}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: aa0d2e694a965c72b5adc0c7779b81e850db46e6
1 file changed