Fix the week_1 http server section

[barneymorris]

At week_1/http/cmd/http_client/main.go
this line

getPostfix  =  "/notes/%d"

has to be

getPostfix  =  "/notes/{id}"

because otherwise each time you client call the server it always get 404.

From go-chi docs:

// Regexp url parameters:
r.Get("/{articleSlug:[a-z-]+}", getArticleBySlug)                // GET /articles/home-is-toronto

[DementevVV]

const (
    getPostfix = "/notes/%s" // Use a string parameter
)

r.Get(fmt.Sprintf(getPostfix, "{id}"), getNoteHandler)