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/docker/main.go

@@ -22,5 +22,5 @@ func main() {
 		ctx.Writef("id: %d", ctx.Params().GetUintDefault("id", 0))
 	})
 
-	app.Run(iris.Addr(*addr))
+	app.Listen(*addr)
 }