Improve import locations

judge/admin/interface.py

@@ -1,6 +1,7 @@
 from django.contrib import admin
 from django.contrib.auth.models import User
-from django.contrib.flatpages.admin import FlatPageAdmin as OldFlatPageAdmin, FlatpageForm as OldFlatpageForm
+from django.contrib.flatpages.admin import FlatPageAdmin as OldFlatPageAdmin
+from django.contrib.flatpages.forms import FlatpageForm as OldFlatpageForm
 from django.forms import ModelForm
 from django.urls import NoReverseMatch, reverse, reverse_lazy
 from django.utils.html import format_html

judge/highlight_code.py

@@ -1,4 +1,5 @@
-from django.utils.html import format_html, mark_safe
+from django.utils.html import format_html
+from django.utils.safestring import mark_safe
 
 __all__ = ['highlight_code']
 

judge/views/contests.py

@@ -23,8 +23,8 @@
 from django.utils.safestring import mark_safe
 from django.utils.timezone import make_aware
 from django.utils.translation import gettext as _, gettext_lazy
-from django.views.generic import ListView, TemplateView
-from django.views.generic.detail import DetailView, SingleObjectMixin, View
+from django.views.generic import ListView, TemplateView, View
+from django.views.generic.detail import DetailView, SingleObjectMixin
 from django.views.generic.list import BaseListView
 from icalendar import Calendar as ICalendar, Event
 from reversion import revisions