Fix viewing wiki commit on empty repo (#28040) (#28044)

Backport #28040 by @JakobDev

Fixes https://codeberg.org/forgejo/forgejo/issues/1758

For some weird reason we need to cast this nil.

Co-authored-by: JakobDev <jakobdev@gmx.de>
(cherry picked from commit 124a9957d0)

routers/web/repo/middlewares.go

@@ -16,7 +16,6 @@ import (
 // SetEditorconfigIfExists set editor config as render variable
 func SetEditorconfigIfExists(ctx *context.Context) {
 	if ctx.Repo.Repository.IsEmpty {
-		ctx.Data["Editorconfig"] = nil
 		return
 	}