[internal #1848537] Upgrade scripts to use Python3

    shebang in DsRestAPI.py changed to call python3

Change-Id: I38b2b916d4c70540faaecd821b5d8d6d1006a112
Signed-off-by: József Gyürüsi <jozsef.gyurusi@ericsson.com>

src/DsRestAPI/Api/Python/DsRestAPI.py

-#!/usr/bin/env python
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 #///////////////////////////////////////////////////////////////////////////////
 #// Copyright (c) 2000-2019 Ericsson Telecom AB                               //