Swift proxy: fix packages installation

Install the swift package on ubuntu to get swift-ring-builder.

Install the same packages on debian and ubuntu.

Change-Id: I3ee1d0c13d03a3938642774fb5699fd18c1cea81
Closes-Bug: #1318028
Backport: icehouse
(cherry picked from commit f05876343a9a22c8b03de88a9b3c9a17ddcbff45)
Merge "Swift proxy: fix packages installation" into stable/icehouse