Fix crash on webhooks create/destroy CSV activities

I'm also adding a template for 500 status code for CSV.

Fixes #994

Signed-off-by: Miquel Sabaté Solà <msabate@suse.com>

app/controllers/errors_controller.rb

@@ -2,6 +2,8 @@
 # configurations too. Moreover, this way we get richer pages while sharing as
 # much code as possible.
 class ErrorsController < ApplicationController
+  respond_to :html, :csv
+
   skip_before_action :check_requirements
   skip_before_action :authenticate_user!
   skip_before_action :force_update_profile!

app/views/errors/500.csv.slim

@@ -0,0 +1 @@
+Internal Server Error

app/views/public_activity/webhook/_create.csv.slim

@@ -1 +1,4 @@
-= CSV.generate_line(['webhook', activity.trackable.url, 'create', '-', activity.owner.username, activity.created_at, "owned by namespace #{activity.trackable.namespace.name}"])
+- if activity.trackable
+  = CSV.generate_line(['webhook', activity.trackable.url, 'create', '-', activity.owner.username, activity.created_at, "owned by namespace #{activity.trackable.namespace.name}"])
+- else
+  = CSV.generate_line(['webhook', activity.parameters[:webhook_host], 'create', '-', activity.owner.username, activity.created_at, "owned by namespace #{activity.parameters[:namespace_name]}"])

app/views/public_activity/webhook/_destroy.csv.slim

@@ -1 +1 @@
-= CSV.generate_line(["webhook", activity.trackable.url, "destroy", "-", activity.owner.username, activity.created_at, "owned by namespace #{activity.trackable.namespace.name}"])
+= CSV.generate_line(["webhook", activity.parameters[:webhook_host], "destroy", "-", activity.owner.username, activity.created_at, "owned by namespace #{activity.parameters[:namespace_name]}"])