Change the default packages url from compass http server to opnfv artifacts

Change the default packages url from compass http server to opnfv artifacts

JIRA: COMPASS-544

Currently compass4nfv uses compass http server to store those packages used in
building ISO. This is not propriate in OPNFV community. So we push all the packages
into opnfv artifacts repo and change the package url used in compass to opnfv
artifacts repo url.

Change-Id: I9661f2d893767e18c037ba9de5f54933f48ce466
Signed-off-by: Yifei Xue <xueyifei@huawei.com>
(cherry picked from commit 5cee19684b16e80b131cc3b5441781a3c6a7f971)