Error when authorizing through configuration file config.yml

There are problems when the Gohtttserver application is running through the configuration file: [testdata/config.yml](https://github.com/codeskyblue/gohttpserver/blob/df32f57005d9f02ee08a89f237a711316b992376/testdata/config.yml). When you launch the app
`$ gohttpserver --conf=config.yml`
using only the config.yml configuration file:
```
---
# Configuration Go HTTP Server
# [Link](https://github.com/codeskyblue/gohttpserver )
#
root: ./dir
port: 1234
auth-type: http
auth-http: username1:password1
```
Then the application is allowed on the site without any authorization.
When you specify the same parameters via the command line, the application requires authorization.
`$ gohttpserver --conf=config.yml --auth-type http --auth-http username1:password1`
This has been verified with basic authorization, OpenID, OAuth2.

Start by comparing how testdata/config.yml is parsed with how the --auth-type and --auth-http command-line options are applied. Run gohttpserver --conf=config.yml and the equivalent command-line invocation, then verify that configuration-file authentication is enforced for basic authorization and the other reported authorization modes.

Written by the indexing model from the issue text.