Fix https://bz.apache.org/bugzilla/show_bug.cgi?id=62067

      Correctly apply security constraints mapped to the context root using a
URL pattern of ""

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc8.5.x/trunk@1823307 13f79535-47bb-0310-9956-ffa450edef68