Make strip_package.py non-executable.

This script should only be run via a wrapper (/usr/bin/strip_package),
or else strange errors occur.

BUG=None
TEST=None

Change-Id: If16ca5fedb1d0b7efb67fd5120ae7ba97f0d5a54
Reviewed-on: https://chromium-review.googlesource.com/275713
Trybot-Ready: Gilad Arnold <garnold@chromium.org>
Tested-by: Gilad Arnold <garnold@chromium.org>
Reviewed-by: Bertrand Simonnet <bsimonnet@chromium.org>
Commit-Queue: Gilad Arnold <garnold@chromium.org>
1 file changed