main takes args starting from 1, not 0.

TBR=agable@chromium.org
BUG=261738

Review URL: https://codereview.chromium.org/212223002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@259521 0039d316-1c4b-4281-b951-d872f2087c98