fix contributors link

Author: lalop

README.md

@@ -110,7 +110,7 @@ You can help us by:
 ## Contributors
 
 This project exists thanks to all the people who contribute. [[Contribute](CONTRIBUTING.md)].
-<a href="graphs/contributors"><img src="https://opencollective.com/libresh/contributors.svg?width=890&button=false" /></a>
+<a href="https://github.com/indiehosters/libre.sh/graphs/contributors"><img src="https://opencollective.com/libresh/contributors.svg?width=890&button=false" /></a>
 
 
 ## Backers