VPN server: Ignore failure to stop ipsec

The test system may race with the chroot in shutting down the
ipsec process.  If the test system loses the race "ipsec stop"
will fail.  We can safely ignore this failure.

BUG=chromium:520775
TEST=Run this test

Change-Id: I02fbf472fb40cb5e7afe1caf27c1c96402d07a98
Reviewed-on: https://chromium-review.googlesource.com/293632
Reviewed-by: mukesh agrawal <quiche@chromium.org>
Commit-Queue: Paul Stewart <pstew@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
2 files changed