Merge pull request #22687 from haoshuwei/fix-docs-securitymd

Fixing security.md
(cherry picked from commit edf5e097a2ee1e1b90a6634d6fa6cf1547dff65c)

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

docs/security/security.md

@@ -52,8 +52,8 @@ How mature is the code providing kernel namespaces and private
 networking? Kernel namespaces were introduced [between kernel version
 2.6.15 and
 2.6.26](http://lxc.sourceforge.net/index.php/about/kernel-namespaces/).
-This means that since July 2008 (date of the 2.6.26 release, now 7 years
-ago), namespace code has been exercised and scrutinized on a large
+This means that since July 2008 (date of the 2.6.26 release
+), namespace code has been exercised and scrutinized on a large
 number of production systems. And there is more: the design and
 inspiration for the namespaces code are even older. Namespaces are
 actually an effort to reimplement the features of [OpenVZ](