Bug 1878 Speed up Artifactory search

The addition of the build parameter to the Artifactory search results
in what would appear to be a full index scan, taking over 2 minutes
to complete.  With this change, we still get the exact artifact
we need, however the search completes in less than 1 second.

Fixes Bug 1878

Change-Id: Ibe5987e06cac39e3651b9dbec61993c0cfb567b8
Signed-off-by: beierlm <mark.beierl@canonical.com>