Fix bug in jobs_power length ValueError exception message

            _running_jobs = [job for job in self.running if job.state == JobState.RUNNING]

            if len(jobs_power) != len(_running_jobs):

                raise ValueError(f"Jobs power list of length ({len(jobs_power)}) should have ({len(running_jobs)}) items.")

                raise ValueError(f"Jobs power list of length ({len(jobs_power)}) should have ({len(_running_jobs)}) items.")

            for i, job in enumerate(_running_jobs):

                if job.running_time % self.config['TRACE_QUANTA'] == 0:

                    job.power_history.append(jobs_power[i] * len(job.scheduled_nodes))