[master] b4068d3 minor update

[Lasse Karstensen]

commit b4068d3ead5974626bfae87a01bda521a5af0fa3
Author: benc <benc at redpill-linpro.com>
Date:   Sun Mar 16 12:55:16 2014 +0100

    minor update

diff --git a/doc/sphinx/users-guide/purging.rst b/doc/sphinx/users-guide/purging.rst
index 2be32e3..214fe81 100644
--- a/doc/sphinx/users-guide/purging.rst
+++ b/doc/sphinx/users-guide/purging.rst
@@ -21,7 +21,7 @@ A *purge* is what happens when you pick out an object from the cache
 and discard it along with its variants. Usually a purge is invoked
 through HTTP with the method `PURGE`.
 
-An HTTP purge is similar to a HTTP GET request, except that the
+A HTTP purge is similar to a HTTP GET request, except that the
 *method* is `PURGE`. Actually you can call the method whatever you'd
 like, but most people refer to this as purging. Squid, for example, supports the
 same mechanism. In order to support purging in Varnish you need the