jenkinsfile - watch screen test 8a kill protection

api/Jenkinsfile.ble_test

@@ -87,7 +87,7 @@ pipeline {
                     sh """
                     ssh -o StrictHostKeyChecking=no root@${params.host_ip} -o ServerAliveInterval=60 -o ServerAliveCountMax=120 << EOF
                         while screen -list | grep -q ble_test_${env.TEST_HASH}; do
-                            tail -f /tmp/ble_test_${env.TEST_HASH}.log
+                            tail -f /tmp/ble_test_${env.TEST_HASH}.log || true
                         done   
                     """
                 }