Clean up generation of account webfinger string (#1477)

* Consolidate webfinger string creation under Account#to_webfinger_s

* Introduce Account#local_username_and_domain for consolidation

app/models/account.rb

@@ -120,6 +120,14 @@ class Account < ApplicationRecord
     local? ? username : "#{username}@#{domain}"
   end
 
+  def local_username_and_domain
+    "#{username}@#{Rails.configuration.x.local_domain}"
+  end
+
+  def to_webfinger_s
+    "acct:#{local_username_and_domain}"
+  end
+
   def subscribed?
     !subscription_expires_at.blank?
   end