fix client.HTTPClient() not returning a copy
```
14:26:43 client/client.go:255:9: SA4001: &*x will be simplified to x. It will not copy x. (staticcheck)
14:26:43 	return &*cli.client
```
@@ -252,7 +252,8 @@ func (cli *Client) DaemonHost() string {
// HTTPClient returns a copy of the HTTP client bound to the server
func (cli *Client) HTTPClient() *http.Client {
- return &*cli.client
+ c := *cli.client
+ return &c
}
// ParseHostURL parses a url string, validates the string is a host url, and
