Mark dnsjnio imports as optional. See JSPF-89 
Mark dnsjnio imports as optional. See JSPF-89 

git-svn-id: 00f83033766efed07e2b0af284f6d6b8c92b3c53@1142554 13f79535-47bb-0310-9956-ffa450edef68

chibenwa/james-jspf,apache/james-jspf