add correct line break

Author: Rahul Pratik

SECURITY.md

@@ -2,5 +2,5 @@
 
 If you find a security error please **DO NOT** make an issue /discussion out of it, talk about it publicly, instead report it with the most details possible to [Tamal Das](https://twitter.com/tamalCodes). You can expect an update within the next **36 hours** - if not please be patient.
 
-Thank you.</br>
+Thank you.<br/>
 Team NgoWorld.