Fix level badge

README.md

@@ -437,4 +437,4 @@ To sustain [`Level`](https://github.com/Level) and its activities, become a back
 
 _`leveldown` builds on the excellent work of the LevelDB and Snappy teams from Google and additional contributors. LevelDB and Snappy are both issued under the [New BSD License](http://opensource.org/licenses/BSD-3-Clause). A large portion of `leveldown` Windows support comes from the [Windows LevelDB port](http://code.google.com/r/kkowalczyk-leveldb/) (archived) by [Krzysztof Kowalczyk](http://blog.kowalczyk.info/) ([`@kjk`](https://twitter.com/kjk)). If you're using `leveldown` on Windows, you should give him your thanks!_
 
-[level-badge]: http://leveldb.org/img/badge.svg
+[level-badge]: https://leveljs.org/img/badge.svg