FIX: Selecting VPP packages

FIX: Selecting VPP packages

There is an issue when multiple VPP versions of same commit
but different build is in repository. Artifacts.sh will find
multiple version and cennot properly download only one.

00:00:46.522 ++ apt-get -y download libvppinfra=19.04-rc0~290-gd4295e61a~b2173 19.04-rc0~290-gd4295e61a~b2172 19.04-rc0~290-gd4295e61a~b2171 libvppinfra-dev=19.04-rc0~290-gd4295e61a~b2173 19.04-rc0~290-gd4295e61a~b2172 19.04-rc0~290-gd4295e61a~b2171 <truncated...//pm>

This patch will select latest as the behavior is result of
re-merge effect.

Change-Id: I8ce21244e2b05e60af0ea51107f9138173844330
Signed-off-by: Peter Mikus <pmikus@cisco.com>