Update whatsnew based on doc search.
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 29f3313..4928d13 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -833,7 +833,7 @@
    so ``sys.version_info[0]`` is equivalent to ``sys.version_info.major``
    and so on.
 
-   .. versionchanged:: 2.7
+   .. versionchanged:: 3.1
       Added named component attributes
 
 .. data:: warnoptions