[master] c9ff40d Grammar fix

[Geoff Simmons]

commit c9ff40d9041b951c3b88ad0b425781b6478a1e32
Author: Geoff Simmons <geoff at uplex.de>
Date:   Wed Mar 14 23:35:49 2018 +0100

    Grammar fix

diff --git a/doc/sphinx/whats-new/upgrading-6.0.rst b/doc/sphinx/whats-new/upgrading-6.0.rst
index c3cc3bd..c1bef35 100644
--- a/doc/sphinx/whats-new/upgrading-6.0.rst
+++ b/doc/sphinx/whats-new/upgrading-6.0.rst
@@ -470,7 +470,7 @@ to preserve the previous behavior, see the
 for advice on how to do so.
 
 With the ``resolve=LAZY`` argument of the ``.backend()`` method, the
-shard director will now defer the selection of a a backend to when a
+shard director will now defer the selection of a backend to when a
 backend connection is actually made, which is how all other bundled
 directors work as well. This enables layering the shard director below
 other directors -- you can use ``.backend(resolve=LAZY)`` to set the