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/http_request/read-json/main.go

@@ -60,5 +60,5 @@ func main() {
 	//
 	// The response should be:
 	// Received: main.Company{Name:"iris-Go", City:"New York", Other:"Something here"}
-	app.Run(iris.Addr(":8080"), iris.WithoutServerError(iris.ErrServerClosed), iris.WithOptimizations)
+	app.Listen(":8080", iris.WithoutServerError(iris.ErrServerClosed), iris.WithOptimizations)
 }