fix: tasks api 504 when pipeline is running (#3256)

diff --git a/services/task.go b/services/task.go
index 232db10..43b77cf 100644
--- a/services/task.go
+++ b/services/task.go
@@ -280,16 +280,15 @@
 }
 
 func updateTaskProgress(taskId uint64, progress chan core.RunningProgress) {
-	runningTasks.mu.Lock()
-	defer runningTasks.mu.Unlock()
-
 	data := runningTasks.tasks[taskId]
 	if data == nil {
 		return
 	}
 	progressDetail := data.ProgressDetail
 	for p := range progress {
+		runningTasks.mu.Lock()
 		runner.UpdateProgressDetail(db, log, taskId, progressDetail, &p)
+		runningTasks.mu.Unlock()
 	}
 }