http method 应该保持大写或用户输入时，提示不应该转换

[shuqingzai]

See: https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Methods#%E8%A7%84%E8%8C%83

1. What version of Go and system type/arch are you using?

2. What version of GoFrame are you using?

3. Can this issue be re-produced with the latest release?

4. What did you do?

5. What did you expect to see?

6. What did you see instead?