QtQA: Fix scripts tests insignificance

This reverts commit 1e9f5606d and moves the insignificant_test
config property to correct pro file.

Task-number: QTQAINFRA-708
Change-Id: Id4c6712ae2eef56dbfbd6e0a67012fde27bc1662
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>