Dashboard statistics should use 'period' as the date limiter

The statistics module on the dashboard was using the incorrect query parameter
'stop'. This meant that the module was loading all tickets from the report start
date to the present day. This commit fixes this by using the 'period' parameter
instead.

WHATSNEW.md

@@ -9,6 +9,7 @@ osTicket v1.7.11
   * Fix sorting by ticket number if using sequential numbers
   * Fix corruption of email mailbox if improperly encoded as ISO-8859-1
     without RFC 2047 charset hint (#1332)
+  * Dashboard statistics should use 'period' as the date limiter (#1345)
 
 ### Performance and Security
   * Fix XSS vulnerability in email template management (#1162)

scp/js/dashboard.inc.js

@@ -140,7 +140,7 @@
             method:     'GET',
             dataType:   'json',
             url:        'ajax.php/report/overview/table',
-            data:       {group: group, start: start, stop: stop},
+            data:       {group: group, start: start, period: stop},
             success:    function(json) {
                 var q = $('<table>').attr({'class':'table table-condensed table-striped'}),
                     h = $('<tr>').appendTo($('<thead>').appendTo(q)),