Fix "svn_ra_get_path_relative_to_session undefined" link error.
Fix "svn_ra_get_path_relative_to_session undefined" link error.

* build.conf(client-test): Add libsvn_ra to libs.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion