Removed a bit of builtin_server tests for Python ≤ 2.7.3.

tests/builtin_server/tests.py

@@ -39,17 +39,6 @@ class ServerHandler(simple_server.ServerHandler, object):
         super(ServerHandler, self).error_output(environ, start_response)
         return ['\n'.join(traceback.format_exception(*sys.exc_info()))]
 
-    # Backport of http://hg.python.org/cpython/rev/d5af1b235dab. See #16241.
-    # This can be removed when support for Python <= 2.7.3 is deprecated.
-    def finish_response(self):
-        try:
-            if not self.result_is_file() or not self.sendfile():
-                for data in self.result:
-                    self.write(data)
-                self.finish_content()
-        finally:
-            self.close()
-
 
 class DummyHandler(object):
     def log_request(self, *args, **kwargs):