fix Empty table header

js/grid.filter.js

@@ -1275,7 +1275,7 @@ $.jgrid.extend({
 			$.each($t.p.colModel,function(ci){
 				var cm=this, soptions, select="", sot="=", so, i, st, csv, df, elem, restores,
 				th = $("<th role='columnheader' class='" + base.headerBox+" ui-th-"+$t.p.direction+" "+(cm.labelClasses || "")+"' id='gsh_" + $t.p.id + "_" + cm.name + "'></th>"),
-				thd = $("<div><span style=\"display: none;\"></span></div>"),
+				thd = $("<div><span aria-label=\"empty\" style=\"display: none;\">empty</span></div>"),
 				stbl = $("<table class='ui-search-table' cellspacing='0'><tr><td class='ui-search-oper' headers=''></td><td class='ui-search-input' headers=''></td><td class='ui-search-clear' headers=''></td></tr></table>");
 				if(this.hidden===true) { $(th).css("display","none");}
 				this.search = this.search === false ? false : true;