Update configuration.md with proper link
Configuration.md contains the wrong link to the rebase-helper packit.yml file.
@@ -60,7 +60,7 @@ The list of projects which already have packit config in their upstream reposito
* [user-cont/colin](https://github.com/user-cont/colin/blob/master/.packit.yaml)
* [user-cont/conu](https://github.com/user-cont/conu/blob/master/.packit.yaml)
* [TomasTomecek/sen](https://github.com/TomasTomecek/sen/blob/master/.packit.yaml)
-* [rebase-helper/rebase-helper](https://github.com/rebase-helper/rebase-helper/blob/master/.packit.yaml)
+* [rebase-helper/rebase-helper](https://github.com/rebase-helper/rebase-helper/blob/master/.packit.yml)
### In-progress work
