Update common.inc.js

$.mobile.activePage.data('url') seems to be more stable than drupalgap.path. I think it has to do with when drupalgap.path is getting updated. If you click on a node from a listview, view the node, then click the back button, you will get the wrong path with drupalgap.path. I think this fixes issue https://github.com/signalpoint/DrupalGap/issues/67 .