t_bootstram():  Use PySys_WriteStderr() instead of fprintf(stderr,...).

This closes bug #117324.
diff --git a/Modules/threadmodule.c b/Modules/threadmodule.c
index 97ab4e1..e0afde5 100644
--- a/Modules/threadmodule.c
+++ b/Modules/threadmodule.c
@@ -197,7 +197,7 @@
 		if (PyErr_ExceptionMatches(PyExc_SystemExit))
 			PyErr_Clear();
 		else {
-			fprintf(stderr, "Unhandled exception in thread:\n");
+			PySys_WriteStderr("Unhandled exception in thread:\n");
 			PyErr_PrintEx(0);
 		}
 	}