update security policy, to use GitHub instead of email

Author: Byron

Diff for: SECURITY.md

@@ -11,5 +11,4 @@ Only the latest version of GitPython can receive security updates. If a vulnerab
 
 ## Reporting a Vulnerability
 
-Please report private portions of a vulnerability to [email protected] that would help to reproduce and fix it. To receive updates on progress and provide
-general information to the public, you can create an issue [on the issue tracker](https://github.com/gitpython-developers/GitPython/issues).
+Please report private portions of a vulnerability to <https://github.com/gitpython-developers/GitPython/security/advisories/new>. Doing so helps to receive updates and collaborate on the matter, without disclosing it publicliy right away.