Update .github/SECURITY.md

Co-authored-by: Addison <8360474+addison74@users.noreply.github.com>

Author: sreichel

.github/SECURITY.md

@@ -16,7 +16,7 @@ We will keep the details of your security vulnerability report private and only
 
 To report a vulnerability, please *DO NOT* open a public Issue or Pull Request.
 
-Please email your security vulnerability report to security@openmage.org along with your GitHub user name so that once we create a security advisory you may be added to it as a collaborator for further review.
+Please email your security vulnerability report to security@openmage.org along with your GitHub username so that once we create a security advisory you may be added to it as a collaborator for further review.
 
 We will review the advisory and work with you to find a suitable solution. We will publicly disclose the vulnerability once a patch is prepared and our community and partners have an easy path forward to apply the patch promptly. We will be sure to give you credit for the vulnerability discovery unless you request otherwise.