examples: replace all app.Run(iris.Addr(...)) with app.Listen just for the shake of simplicity, both are doing the same exact thing as it's described on the http listening first example.

Former-commit-id: d20afb2e899aee658a8e0ed1693357798df93462

_examples/file-server/basic/main.go

@@ -48,5 +48,5 @@ func newApp() *iris.Application {
 
 func main() {
 	app := newApp()
-	app.Run(iris.Addr(":8080"))
+	app.Listen(":8080")
 }