Fix ONAP SDK tests execution using Python 3.7

CentOS build node has not Python3.7 and Python 3.9 is not executed properly

Issue-ID: INT-2219
Signed-off-by: Michal Jagiello <michal.jagiello@t-mobile.pl>
Change-Id: I6fd062e95038a0fdd20ac764fa375c0b7d516428
1 file changed