Fix error when accessing /filters/:id/statuses on glitch-soc (#1837)

I failed to account for glitch-soc's theming system when merging
from upstream.

app/controllers/filters/statuses_controller.rb

@@ -6,6 +6,7 @@ class Filters::StatusesController < ApplicationController
   before_action :authenticate_user!
   before_action :set_filter
   before_action :set_status_filters
+  before_action :set_pack
   before_action :set_body_classes
 
   PER_PAGE = 20
@@ -25,6 +26,10 @@ class Filters::StatusesController < ApplicationController
 
   private
 
+  def set_pack
+    use_pack 'admin'
+  end
+
   def set_filter
     @filter = current_account.custom_filters.find(params[:filter_id])
   end