我如何处理Golang HTTP服务器中的意外错误

This is simple http server in golang.

package main

import (
    "fmt"
    "net/http"
)

func main() {
    http.HandleFunc("/", func (w http.ResponseWriter, r *http.Request) {
        fmt.Fprintf(w, "Welcome to my website!")
    })

    fs := http.FileServer(http.Dir("static/"))
    http.Handle("/static/", http.StripPrefix("/static/", fs))

    http.ListenAndServe(":80", nil)
}

My question is this, why when i put % to url. Go server cause 400 Bad Request error

Example:

http://localhost:80/anythink%

When someone request bad link like this in go http server, cause security information leak. if smart enough detect server side type. The main question is this to how to handle this error