Fix typo in CVE-2011-4815.yml notes

Author: jasnow

rubies/ruby/CVE-2011-4815.yml

@@ -23,4 +23,4 @@ related:
     - https://github.com/advisories/GHSA-xpr8-vpc7-7vfc
     - http://www.osvdb.org/show/osvdb/78118
 notes: |
-  - CVE-2011-4838 is the same issue but JRuby.
+  - CVE-2011-4838 is the same issue but for JRuby.