Correct regex when message starts with [SECURITY]

Doesn't need to start at the beginning of the line.

lib/index.js

@@ -262,7 +262,7 @@ const cherryPickPR = async (
   }
 };
 
-const SHORT_MSG_REGEX = /^Bump ([\w-@\/]+) from ([\w\.-]+) to ([\w\.-]+)/;
+const SHORT_MSG_REGEX = /Bump ([\w-@\/]+) from ([\w\.-]+) to ([\w\.-]+)/;
 const PKG_MANAGER_REGEX = /dependabot\/([\w-]+)/;
 const EXTRACT_FROM_REGEX = /^\-(.*)$/m;
 const EXTRACT_TO_REGEX = /^\+(.*)$/m;