[Jenkins] Quickfix for BuildDiscarder due to Jenkins update.

Jenkinsfile

@@ -38,4 +38,4 @@ node('master') {
     }
 }
 
-properties ([[$class: 'BuildDiscarderProperty', strategy: [$class: 'LogRotator', artifactDaysToKeepStr: '', artifactNumToKeepStr: '5', daysToKeepStr: '', numToKeepStr: '25']]])
+properties ([[$class: 'org.jenkinsci.plugins.workflow.job.properties.BuildDiscarderProperty', strategy: [$class: 'LogRotator', artifactDaysToKeepStr: '', artifactNumToKeepStr: '5', daysToKeepStr: '', numToKeepStr: '25']]])