Fixed error in ci_stage_3.groovy file

There was a typo in threshold variables.

Change-Id: Ib4cf608e0694e89f015212c6a011d4faa001d88c
Signed-off-by: aguilard <e.dah.tid@telefonica.com>

jenkins/ci-pipelines/ci_stage_3.groovy

@@ -69,8 +69,8 @@ void run_robot_systest(String tagName,
                        String hostfile=null,
                        String jujuPassword=null,
                        String osmRSAfile=null,
-                       String passThreshold='0.0',
-                       String unstableThreshold='0.0') {
+                       String pass_th='0.0',
+                       String unstable_th='0.0') {
     tempdir = sh(returnStdout: true, script: 'mktemp -d').trim()
     if ( !envfile ) {
         sh(script: "touch ${tempdir}/env")