attempt fix for libobjc2 detection


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@36158 72102866-910b-0410-8b05-ffd578937521
suppress compiler warning


git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@36159 72102866-910b-0410-8b05-ffd578937521