Reset secret of web app that could have been exposed by Doorkeeper (#13688)

There are no obvious ways it could be misused, as the secret is not
really used for anything, but it is best to secure it for the future

Follow-up to #13613

db/migrate/20200510110808_reset_web_app_secret.rb

@@ -0,0 +1,15 @@
+class ResetWebAppSecret < ActiveRecord::Migration[5.2]
+  disable_ddl_transaction!
+
+  def up
+    web_app = Doorkeeper::Application.find_by(superapp: true)
+
+    return if web_app.nil?
+
+    web_app.renew_secret
+    web_app.save!
+  end
+
+  def down
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2020_05_08_212852) do
+ActiveRecord::Schema.define(version: 2020_05_10_110808) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"