devserver: set shebangs to python2

This code isn't Python 3 compatible yet, so make sure it's pinned to 2.

BUG=chromium:998225
TEST=tests pass when python->python3

Change-Id: Ieda3edde14bd3b272fd746b5377784b07fa5b3df
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/1773508
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
10 files changed