Fix users environment version of python2 in op-test script.
Fix users environment version of python2 in op-test script.

Fixes: https://github.com/open-power/op-test-framework/issues/255

Signed-off-by: Pridhiviraj Paidipeddi <fd8ea14509c256cbd04eaa4ee745a213945e70a1@linux.vnet.ibm.com>

open-power/op-test-framework,open-power/op-test-framework,open-power/op-test-framework