Datepicker: Set explicit button text in demo

Fixes #9626
Closes jquerygh-1283

Author: scottgonzalez

demos/datepicker/icon-trigger.html

@@ -14,7 +14,8 @@
 		$( "#datepicker" ).datepicker({
 			showOn: "button",
 			buttonImage: "images/calendar.gif",
-			buttonImageOnly: true
+			buttonImageOnly: true,
+			buttonText: "Select date"
 		});
 	});
 	</script>