MM-8834: Changes separator between jobs message and details. (#8589)

jobs/jobs.go

@@ -81,7 +81,7 @@ func (srv *JobServer) SetJobError(job *model.Job, jobError *model.AppError) *mod
 	if job.Data == nil {
 		job.Data = make(map[string]string)
 	}
-	job.Data["error"] = jobError.Message + " (" + jobError.DetailedError + ")"
+	job.Data["error"] = jobError.Message + " — " + jobError.DetailedError
 
 	if result := <-srv.Store.Job().UpdateOptimistically(job, model.JOB_STATUS_IN_PROGRESS); result.Err != nil {
 		return result.Err