Fix for testing the raise of expected errors in systemtests.
The systemtest will not be tested, if python version is under version 2.7.
Bug #22801 (https://gna.org/bugs/?22801): Failure of the relax test suite on Python 2.5.
Authored by: tlinnet 2014-10-13
Parent: [r26259]
Child: [r26261]
