Update piwik.php

Disabled Page View Tracking by commenting out lines 374-375.  

To get page view tracking in a MijoShop/Joomla environment, we need to use a plugin that will appear across the entire site, like nfrPiwik.  That will allow us to track page views on every page of the website... articles, forms, etc.

Link to Joomla plugin: http://extensions.joomla.org/extensions/site-management/analytics/site-analytics-cloud-based/10422