Redirect on changing user and organization name

[kasbah]

Currently gitea redirects repository URLs when you change the repository name (implemented in #807), but if you change a username or organization name then gitea won't redirect.

I am just wondering if there is interest in having redirects on username and organization name change implemented as well.

[lafriks]

That is tricky one as somebody can create org or user with old name so it would not be consistent and could lead to potential problems

[kasbah]

There is a similar problem for just changing repository names that was already solved in #807 I believe. The solution is to not redirect when a new org/user takes the old name. This is also how Github does it.

If the new owner of your old username creates a repository with the same name as your repository, that will override the redirect entry and your redirect will stop working.

[lunny]

@lafriks What's the problems? But we have implemented the redirects when you change repository name.

[lafriks]

No problem, could be some risks but I'm fine if someone sends PR for this