fix incorrect repo url when changed the case of ownername (go-gitea#25733) (go-gitea#25881)

Backport go-gitea#25733 by @hiifong

When only the casing of the username changes, update the owner name of the repo,
and keep the original logic consistent with other conditions.

example: assume your username is `gitea`, lowercase username is `gitea` too,
repo URL is `.../gitea/{repo}`.
You change your username to `Gitea`, `GiTea` or something like that,
as long as the lowercase username is still `gitea`, the repo URL remained `.../gitea/{repo}`.

this pr keeps the new username consistent with the repo URL.

Before:

![image](https://github.com/go-gitea/gitea/assets/89133723/84177296-f0ff-4176-84f1-1f9ec3f5b86f)
![image](https://github.com/go-gitea/gitea/assets/89133723/8f8f4a12-ecdd-4dec-af89-85c009b0ccfe)

After: 

![image](https://github.com/go-gitea/gitea/assets/89133723/0564edb6-9467-405a-8cd4-d6f70e6f614b)
![image](https://github.com/go-gitea/gitea/assets/89133723/554ecd6e-e5a1-43bc-a46d-99e988c2ff58)

Co-authored-by: hiifong <i@hiif.ong>

Author: GiteaBot

routers/web/org/setting.go

@@ -89,7 +89,6 @@ func SettingsPost(ctx *context.Context) {
 		// reset ctx.org.OrgLink with new name
 		ctx.Org.OrgLink = setting.AppSubURL + "/org/" + url.PathEscape(form.Name)
 		log.Trace("Organization name changed: %s -> %s", org.Name, form.Name)
-		nameChanged = false
 	}
 
 	// In case it's just a case change.
@@ -130,11 +129,6 @@ func SettingsPost(ctx *context.Context) {
 				return
 			}
 		}
-	} else if nameChanged {
-		if err := repo_model.UpdateRepositoryOwnerNames(org.ID, org.Name); err != nil {
-			ctx.ServerError("UpdateRepository", err)
-			return
-		}
 	}
 
 	log.Trace("Organization setting updated: %s", org.Name)

services/user/user.go

@@ -58,7 +58,7 @@ func RenameUser(ctx context.Context, u *user_model.User, newUserName string) err
 			u.Name = oldUserName
 			return err
 		}
-		return nil
+		return repo_model.UpdateRepositoryOwnerNames(u.ID, newUserName)
 	}
 
 	ctx, committer, err := db.TxContext(ctx)