Change DeprecatedAlgorithmCheckerTest.py example re #7072

I change it to use DiffractionFocussing which I do not intend to remove for release 3.0, because it is used by a system test.

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>

Code/Mantid/Framework/PythonInterface/test/python/mantid/api/DeprecatedAlgorithmCheckerTest.py

@@ -12,7 +12,7 @@ def test_non_deprecated_algorithm_returns_empty_string_from_isDeprecated(self):
         self.assertTrue(len(msg) == 0)
 
     def test_deprecated_algorithm_returns_non_empty_string_from_isDeprecated(self):
-        deprecation_check = DeprecatedAlgorithmChecker("GetMaskedDetectors",-1)
+        deprecation_check = DeprecatedAlgorithmChecker("DiffractionFocussing",-1)
         msg = deprecation_check.isDeprecated()
         self.assertTrue(len(msg) > 0)