Remove the "future release" notice in user release docs for 6.2.

Unless we think of something else to add, this version of the docs
is suitable for the 6.2 release.

doc/sphinx/whats-new/changes-6.2.rst

-**Note: This is a working document for a future release, with running
-updates for changes in the development branch. For changes in the
-released versions of Varnish, see:** :ref:`whats-new-index`
-
 .. _whatsnew_changes_2019_03:
 
 %%%%%%%%%%%%%%%%%%%%%%

doc/sphinx/whats-new/index.rst

@@ -11,10 +11,6 @@ entail.
 Varnish 6.2
 -----------
 
-**Note: These are working documents for a future release, with running
-updates for changes in the development branch. For changes in the
-released versions of Varnish, see the chapters listed below.**
-
 .. toctree::
    :maxdepth: 2
 

doc/sphinx/whats-new/upgrading-6.2.rst

-**Note: This is a working document for a future release, with running
-updates for changes in the development branch. For changes in the
-released versions of Varnish, see:** :ref:`whats-new-index`
-
 .. _whatsnew_upgrading_2019_03:
 
 %%%%%%%%%%%%%%%%%%%%%%%%