Fixed error "STILL_ACTIVE" when using <job stderr_log_level="error"> (JS-1329)

A job may abort with the error message "STILL_ACTIVE" when the following conditions are met.

• Use of <job stderr_log_level="error"> (JS-1329)
• Local execution (no Agent)
• No pre-processing is used
• This behavior occurs preferably for environments with slow performance

The error may not occur if the shell script terminates immediately after the stderr output.