remove unused coding=utf-8

oj/custom_settings.example.py

@@ -1,4 +1,2 @@
-# coding=utf-8
-
 # please set your own SECRET_KEY to a long random string
 # SECRET_KEY = ""

oj/db_router.py

@@ -1,6 +1,3 @@
-# coding=utf-8
-
-
 class DBRouter(object):
     def db_for_read(self, model, **hints):
         if model._meta.app_label == "submission":

oj/urls.py

@@ -1,4 +1,3 @@
-# coding=utf-8
 from django.conf.urls import include, url
 
 urlpatterns = [