use head method instead of :nothing option

app/controllers/diaspora_federation/fetch_controller.rb

@@ -17,7 +17,7 @@ module DiasporaFederation
                                                            entity.author, "/fetch/#{params[:type]}/#{params[:guid]}")
         end
       else
-        render nothing: true, status: 404
+        head :not_found
       end
     end
 

app/controllers/diaspora_federation/h_card_controller.rb

@@ -10,7 +10,7 @@ module DiasporaFederation
       person_hcard = DiasporaFederation.callbacks.trigger(:fetch_person_for_hcard, params[:guid])
 
       if person_hcard.nil?
-        render nothing: true, status: 404
+        head :not_found
       else
         logger.info "hcard profile request for: #{person_hcard.nickname}:#{person_hcard.guid}"
         # rubocop:disable Rails/OutputSafety

app/controllers/diaspora_federation/receive_controller.rb

@@ -16,7 +16,7 @@ module DiasporaFederation
 
       DiasporaFederation.callbacks.trigger(:queue_public_receive, data, legacy)
 
-      render nothing: true, status: 202
+      head :accepted
     end
 
     # Receives private messages for a user
@@ -30,7 +30,7 @@ module DiasporaFederation
 
       success = DiasporaFederation.callbacks.trigger(:queue_private_receive, params[:guid], data, legacy)
 
-      render nothing: true, status: success ? 202 : 404
+      head success ? :accepted : :not_found
     end
 
     private
@@ -39,7 +39,7 @@ module DiasporaFederation
     # @deprecated
     def check_for_xml
       legacy_request = request.content_type.nil? || request.content_type == "application/x-www-form-urlencoded"
-      render nothing: true, status: 422 if params[:xml].nil? && legacy_request
+      head :unprocessable_entity if params[:xml].nil? && legacy_request
     end
 
     def data_for_public_message(legacy)

app/controllers/diaspora_federation/webfinger_controller.rb

@@ -38,7 +38,7 @@ module DiasporaFederation
       person_wf = find_person_webfinger(params[:q]) if params[:q]
 
       if person_wf.nil?
-        render nothing: true, status: 404
+        head :not_found
       else
         logger.info "webfinger profile request for: #{person_wf.acct_uri}"
         render xml: person_wf.to_xml, content_type: "application/xrd+xml"