Revert "number of thread is wrong...?"

This reverts commit ffe34b21fbdcf9a61762d830bb7e8b7e9acc05b4.

backend_refactor/app.py

@@ -30,6 +30,7 @@ with app.app_context():
     # db.drop_all()
     db.create_all()
 
+init_workers()
 
 try:
     os.mkdir(UPLOAD_DIR + "/result")
@@ -66,5 +67,4 @@ def error_handler(e):
 
 
 if __name__ == '__main__':
-    init_workers()
     app.run()