[_746] change name of test (& correct issue number appended)

Author: d-w-moore

irods/test/data_obj_test.py

@@ -2989,7 +2989,7 @@ def test_handling_of_termination_signals_during_multithread_put__issue_722(self)
 
         test_put__issue_722(self)
 
-    def test_modified_default_sorting_of_replicas__issue_647(self):
+    def test_modified_sorting_of_replicas__issue_647(self):
         basename = unique_name(my_function_name(), datetime.now()) + '_dataobj_647'
         with self.create_simple_resc() as newResc1, self.create_simple_resc() as newResc2:
             data = helpers.make_object(self.sess, f'{helpers.home_collection(self.sess)}/{basename}')