Improve the 'How often should I mirror' section: metion locking, remove some usage of 'you' and make more gender neutral.

svn path=/head/; revision=46666

en_US.ISO8859-1/articles/hubs/article.xml

@@ -352,13 +352,12 @@
    <sect2 xml:id="mirror-how-often">
      <title>How often should I mirror?</title>
      <para>
-       Every mirror should be updated on a regular
-       basis. You will certainly need some script
-       framework for it that will be called by
-       &man.cron.8;. Since nearly every admin
-       does this his own way, we cannot give
-       specific instructions. It could work
-       like this:
+       Every mirror should be updated at a minimum of once per day.
+       Certainly a script with locking to prevent multiple runs
+       happening at the same time will be needed to run from
+       &man.cron.8;. Since nearly every admin does this in their own
+       way, specific instructions cannot be provided.  It could work
+       something like this:
      </para>
      <procedure>
        <step>