Add test case that ensures there error messages in distributed mode a…

…re not quoted an extra time.

locust/test/test_main.py

@@ -2129,6 +2129,8 @@ def test_processes_ctrl_c(self):
             self.assertIn("(index 3) reported as ready", stderr)
             self.assertIn("The last worker quit, stopping test", stderr)
             self.assertIn("Shutting down (exit code 0)", stderr)
+            # ensure no weird escaping in error report. Not really related to ctrl-c...
+            self.assertIn("GET /: ConnectionRefusedError(61, 'Connection refused')", stderr)
 
     @unittest.skipIf(os.name == "nt", reason="--processes doesnt work on windows")
     def test_workers_shut_down_if_master_is_gone(self):