Update SECURITY.md

.github/SECURITY.md

@@ -3,7 +3,7 @@
 ## Supported Versions
 
 We only support the latest production version, deployed to <https://content.minetest.net>.
-See the [releases page](https://github.com/minetest/contentdb/releases).
+This is usually the latest `master` commit.
 
 ## Reporting a Vulnerability
 
@@ -12,8 +12,5 @@ to give us time to fix them. You can do that by using one of the methods outline
 
 * https://rubenwardy.com/contact/
 
-Depending on severity, we will either create a private issue for the vulnerability
-and release a security update, or give you permission to file the issue publicly.
-
 For more information on the justification of this policy, see
 [Responsible Disclosure](https://en.wikipedia.org/wiki/Responsible_disclosure).