Fix issue with empty table and TR. Changed to use header to calculate count of columns

Author: sshishov

static/hospital/js/base.js

@@ -1,7 +1,7 @@
 // Call the dataTables jQuery plugin
 $(document).ready(function() {
   $('#patientHistoryTable').DataTable({
-    'order': [[ $("#patientHistoryTable > tbody > tr:first > td").length - 1, "desc" ]],
+    'order': [[ $("#patientHistoryTable > tbody > th > td").length - 1, "desc" ]],
     'language': {
       'url': "//cdn.datatables.net/plug-ins/1.10.16/i18n/Russian.json"
     },