Remove can_modify context variable, use is_staff instead

For both ban and modify actions, we trust staff users to not abuse
otherwise-secret scripts and links. We don't supply "can_modify" context
variable anymore and just use user.is_staff instead. The same goes for
ban links and scripts.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

board/views.py

@@ -137,8 +137,6 @@ class BoardView(BoardMixin, TemplateView):
         kwargs["pages"] = range(1, last_page + 1)
         kwargs["last_page"] = last_page
         kwargs["max_upload_size"] = settings.MAX_UPLOAD_SIZE
-        kwargs["can_modify"] = can_modify(self.request.user)
-
         return super(BoardView, self).get_context_data(**kwargs)
 
 
@@ -199,11 +197,6 @@ class PostModifySuccessView(PermissionRequiredMixin, ActionSuccessView):
     def has_permission(self) -> bool:
         return can_modify(self.request.user)
 
-    def get_context_data(self, **kwargs):
-        context = super().get_context_data(**kwargs)
-        context["can_modify"] = self.has_permission()
-        return context
-
 
 class ReplyCreateView(CreateView):
     model = Post
@@ -248,8 +241,6 @@ class PostView(TemplateView):
         post_id = self.kwargs["id"]
         kwargs["post"] = get_object_or_404(Post, id=post_id)
         kwargs["max_upload_size"] = settings.MAX_UPLOAD_SIZE
-        kwargs["can_modify"] = can_modify(self.request.user)
-
         return super(PostView, self).get_context_data(**kwargs)
 
     def dispatch(self, request, *args, **kwargs):