Revert "Enforce SVN mirror URL for WebRTC trybot recipe."
Revert "Enforce SVN mirror URL for WebRTC trybot recipe."

This reverts r247213. This is needed to avoid confusion
for internal bots and a better solution is needed long-term
for how to handle these URLs properly.

BUG=337599,385036

Review URL: https://codereview.chromium.org/339113002

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@277662 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build