Fix up link to KEYS file

git-svn-id: https://svn.apache.org/repos/asf/creadur/rat/trunk@1513166 13f79535-47bb-0310-9956-ffa450edef68
Download latest release, Rat 0.10

git-svn-id: https://svn.apache.org/repos/asf/creadur/rat/trunk@1515585 13f79535-47bb-0310-9956-ffa450edef68
Merge remote-tracking branch 'upstream/trunk' into trunk