cros_sdk: improve curl output parsing

Derived from CoreOS commit add4c2e24ca7e23bb3895fdea8fa58eab950f9dc
https://github.com/coreos/chromite/pull/21

    """
    Blindly searching for '200 OK' doesn't work with HTTP/2 which doesn't
    include a text description in the response. Match the status line by
    prefix instead. Seems less foolish anyway.
    """

Might as well future-proof against HTTP revisions up to 9.9 ;)

BUG=chromium:541462, chromium:810207
TEST=`cros_sdk`; set up new chroot; trybots

Cherry picked from master. Conflicts:
* Removed call to logging

Change-Id: I5e88a4b38f357bb08449de302a5c813f572136d2
Inspired-by: Michael Marineau <michael.marineau@coreos.com>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/373685
Tested-by: Harry Pan <gs0622@gmail.com>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Signed-off-by: Alexandru M Stan <amstan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/957712
Reviewed-on: https://chromium-review.googlesource.com/1139879
Tested-by: Mike Frysinger <vapier@chromium.org>
1 file changed