making share counts protocol relative as they are available over HTTPS

This fixes one of the mixed content errors:
![screen shot 2014-11-17 at 11 40 20](https://cloud.githubusercontent.com/assets/1764158/5069157/96bf9d14-6e4e-11e4-84be-dc64d014e7bf.png)
 when fetching over HTTPS (e.g. Preview)