Add owner limit to only view reports (rather than being able to configure and view)

Matti brought up the potential for a mild DoS in the forums, with regard to the reporting tools (he specifically mentions AWstats, but Webalizer is similar).

http://www.virtualmin.com/forums/message-view?message_id=42005

Probably just need a switch to turn the "Edit AWstats Report" link into a "View AWstats Report", if the domain owner doesn't have the ability to modify the schedule and report options.