Fix 405 HTTP status description (#1479)

The https://developer.mozilla.org/en-US/docs/Web/HTTP/Status page do say that the 405 should not be returned for GET and HEAD. But if you click on that 405 link it will open https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/405 , and there there's nothing about mandatory methods.

On that page you will get the RFC link https://tools.ietf.org/html/rfc7231#section-6.5.5 , and again, there's nothing about mandatory methods.

The restful documentation also doesn't talk about mandatory methods for 405: https://restfulapi.net/http-status-codes/

Spring Framework (a well know framework for Java) has some configuration for the Spring Data Rest project that will result in GET requests returning 405.

Since the RFC should be the winner here, and the divergence between the mozilla's pages, I'm proposing this fix to remove the misleading description.
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f