Update Jenkinsfile_test_cvmfs_transaction

jenkins/Jenkinsfile_test_cvmfs_transaction

@@ -33,11 +33,10 @@ pipeline {
                         }
                     } catch (e) {
                         if (!failedNodes.isEmpty()) {
-                            echo ${failedNodes}
                             emailext (
                                 attachLog: true, 
                                 body: "${params.MAILBODY}",
-                                subject: "${params.MAILSUBJECT} [${failedNodes}]",
+                                subject: "${params.MAILSUBJECT} [${failedNodesFormatted}]",
                                 to: "${params.MAILRECIPIENT}"
                             )
                         }