MB: Remove configuration for unexisting bots.

R=kjellander@webrtc.org
BUG=chromium:497757
NOTRY=True

Review-Url: https://codereview.webrtc.org/2507243002
Cr-Original-Commit-Position: refs/heads/master@{#15108}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 3a1c40a60afbc66d5001755393c827eb8bf9430e
1 file changed