bpo-16055: Fixes incorrect error text for int('1', base=1000) (#6980)

Fixes incorrect error text for int('1', base=1000)
and long('1', base=1000).
diff --git a/Objects/intobject.c b/Objects/intobject.c
index 3ab00af..9b27c35 100644
--- a/Objects/intobject.c
+++ b/Objects/intobject.c
@@ -358,7 +358,7 @@
 
     if ((base != 0 && base < 2) || base > 36) {
         PyErr_SetString(PyExc_ValueError,
-                        "int() base must be >= 2 and <= 36");
+                        "int() base must be >= 2 and <= 36, or 0");
         return NULL;
     }