SF bug #1503294.

PyThreadState_GET() complains if the tstate is NULL, but only in debug mode.
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index f9e45fd..c02f1b2 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -561,7 +561,7 @@
 	/* We can arrive here with a NULL tstate during initialization:
 	   try running "python -Wi" for an example related to string
 	   interning.  Let's just hope that no exception occurs then... */
-	tstate = PyThreadState_GET();
+	tstate = _PyThreadState_Current;
 	if (tstate != NULL && tstate->curexc_type != NULL) {
 		/* preserve the existing exception */
 		PyObject *err_type, *err_value, *err_tb;