SF patch #664192 bug #661913: inconsistent error messages between string
                              and unicode

Patch by Christopher Blunck.
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 1a4a754..f18edb0 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -1620,7 +1620,7 @@
 		return NULL;
 	if (result == -1) {
 		PyErr_SetString(PyExc_ValueError,
-				"substring not found in string.index");
+				"substring not found");
 		return NULL;
 	}
 	return PyInt_FromLong(result);
@@ -1659,7 +1659,7 @@
 		return NULL;
 	if (result == -1) {
 		PyErr_SetString(PyExc_ValueError,
-				"substring not found in string.rindex");
+				"substring not found");
 		return NULL;
 	}
 	return PyInt_FromLong(result);