Added missing import to the last commit

boards/views/thread/thread.py

@@ -1,4 +1,5 b''
 from django.core.urlresolvers import reverse
+from django.core.exceptions import ObjectDoesNotExist
 from django.db import transaction
 from django.http import Http404
 from django.shortcuts import get_object_or_404, render, redirect
@@ -38,7 +39,7 b' class ThreadView(BaseBoardView, PostMixi'
     def get(self, request, post_id, form: PostForm=None):
         try:
             opening_post = Post.objects.get(id=post_id)
-        except DoesNotExist:
+        except ObjectDoesNotExist:
             raise Http404
 
         # If this is not OP, don't show it as it is