jenkinsfile - watch screen test 7i new ssh method

api/Jenkinsfile.ble_test

@@ -91,8 +91,9 @@ pipeline {
                             # Loop while the screen session exists
                             while screen -list | grep -q "ble_test_${TEST_HASH}"; do
                                 # Tail the file and flush each line immediately
-                                tail -n +1 -f "/tmp/ble_test_${env.TEST_HASH}.log" | while IFS= read -r line; do
-                                    printf '%s\n' "$line"
+                                tail -n +1 -f "/tmp/ble_test_\\${env.TEST_HASH}.log" |
+                                    while IFS= read -r line; do
+                                        printf '%s\\n' "\\${line}"
                                     done    
                             done
                             EOF