List autodividers: use trim() to avoid issues with newlines and space…

…s in markup. Fixes #5197. Thanks @demonslord !

js/widgets/listview.autodividers.js

@@ -9,7 +9,7 @@ define( [ "jquery", "./listview" ], function( $ ) {
 $.mobile.listview.prototype.options.autodividers = false;
 $.mobile.listview.prototype.options.autodividersSelector = function( elt ) {
 	// look for the text in the given element
-	var text = elt.text() || null;
+	var text = $.trim( elt.text() ) || null;
 
 	if ( !text ) {
 		return null;