Fix PyString_Format so that the "%s" format works again when Unicode is not
enabled.
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 05deb3a..5797eb9 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -4083,7 +4083,9 @@
 					argidx = argidx_start;
 					goto unicode;
 				}
+#endif
 				temp = _PyObject_Str(v);
+#ifdef Py_USING_UNICODE
 				if (temp != NULL && PyUnicode_Check(temp)) {
 					Py_DECREF(temp);
 					fmt = fmt_start;