update path to build_artifacts_ruby.sh in jenkins script

tools/jenkins/build_artifacts.sh

@@ -40,7 +40,7 @@ curr_platform="$platform"
 unset platform  # variable named 'platform' breaks the windows build
 
 if [ "$curr_platform" == "linux" ] && [ "$language" == "ruby" ] ; then
-  ./tools/run_tests/build_artifact_ruby.sh
+  ./tools/run_tests/artifacts/build_artifact_ruby.sh
 else
   python tools/run_tests/task_runner.py -f artifact $language $curr_platform $architecture
 fi