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/upload-files/main.go

@@ -72,7 +72,7 @@ func main() {
 	})
 
 	// start the server at http://localhost:8080 with post limit at 32 MB.
-	app.Run(iris.Addr(":8080"), iris.WithPostMaxMemory(32<<20))
+	app.Listen(":8080", iris.WithPostMaxMemory(32<<20))
 }
 
 func saveUploadedFile(fh *multipart.FileHeader, destDirectory string) (int64, error) {