vnfsdk pkgtools: switch to python3

Switch to python3 for vnfsdk pkgtools' related jenkins job.

Issue-ID: CIMAN-342
Signed-off-by: Lianhao Lu <lianhao.lu@intel.com>
Change-Id: Ic2aa39ea5f28e82870b252a5bdd92c4f1e77c1d7
1 file changed