Merge pull request #158 from nextcloud/reintroduce-hackerone

Reintroduce HackerOne into CONTRIBUTING.md

CONTRIBUTING.md

@@ -12,7 +12,7 @@ If you have questions about how to install or use Nextcloud, please direct these
   - You can also filter by appending e. g. "state:open" to the search string.
   - More info on [search syntax within github](https://help.github.com/articles/searching-issues)
 * This repository ([core](https://github.com/nextcloud/core/issues)) is *only* for issues within the Nextcloud Server code. This also includes the apps: files, encryption, external storage, sharing, deleted files, versions, LDAP, and WebDAV Auth
-* __SECURITY__: Report any potential security bug to us via security@nextcloud.com following our [security policy](https://nextcloud.com/security/) instead of filing an issue in our bug tracker-
+* __SECURITY__: Report any potential security bug to us via [our HackerOne page](https://hackerone.com/nextcloud) or security@nextcloud.com following our [security policy](https://nextcloud.com/security/) instead of filing an issue in our bug tracker.
 * The issues in other components should be reported in their respective repositories: You will find them in our [GitHub Organization](https://github.com/nextcloud/)
 
 * Report the issue using our [template][template], it includes all the information we need to track down the issue.