libweave: Remove chromeos/url_utils.h includes

Code is just inlined.

BUG=brillo:1257
TEST=`FEATURES=test emerge-gizmo libweave`

Change-Id: I61990c758e8fb9bfec35efeed3bf9db8c3975feb
Reviewed-on: https://chromium-review.googlesource.com/293587
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Vitaly Buka <vitalybuka@chromium.org>
Tested-by: Vitaly Buka <vitalybuka@chromium.org>