delete ecxtra dependice

Signed-off-by: Binren Zhnag <zhangbr@elab-plus.com>

flask_app.py

@@ -8,9 +8,6 @@ from flask_apscheduler import APScheduler
 from email_util import EmailUtil
 import decimal
 from report_push import ReportPush
-from flask_mail import Mail, Message
-
-mail = Mail()
 
 app = Flask(__name__)
 # app.config.from_object(Config())