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/structuring/login-mvc-single-responsibility-package/main.go

@@ -27,7 +27,7 @@ func main() {
 	// http://localhost:8080/user/me
 	// http://localhost:8080/user/logout
 	// http://localhost:8080/user/1
-	app.Run(iris.Addr(":8080"), configure)
+	app.Listen(":8080", configure)
 }
 
 func configureMVC(app *mvc.Application) {