fix srtyle

Author: Ariouz

graalpython/lib-python/3/test/test_threading.py

@@ -1808,9 +1808,9 @@ def setUp(self):
 
     def test_excepthook(self):
         with support.captured_output("stderr") as stderr:
-                thread = ThreadRunFail(name="excepthook thread")
-                thread.start()
-                thread.join()
+            thread = ThreadRunFail(name="excepthook thread")
+            thread.start()
+            thread.join()
 
         stderr = stderr.getvalue().strip()
         self.assertIn(f'Exception in thread {thread.name}:\n', stderr)