Ensure test only runs if threads available.

Author: heplesser

testsuite/pytests/sli2py_regressions/test_ticket_293.py

@@ -23,6 +23,7 @@
 import pytest
 
 
+@pytest.mark.skipif_missing_threads
 def test_ticket_293():
     """
     Regression test for Ticket #293.