docs: update SECURITY.md

Signed-off-by: Jason Yan <crazymryan@gmail.com>

Author: CrazyMrYan

SECURITY.md

@@ -7,7 +7,7 @@ currently being supported with security updates.
 
 | Version | Supported          |
 | ------- | ------------------ |
-| >= 2.0.0-plus  | :white_check_mark: |
+| >=v2.0.0-beta.1-plus  | :white_check_mark: |
 
 ## Reporting a Vulnerability