feat: privacy mode

Adds support for hiding IP addresses & hostnames associated with clients sending
authenticated mail in to Postal over SMTP and HTTP

app/controllers/servers_controller.rb

@@ -41,7 +41,7 @@ class ServersController < ApplicationController
 
   def update
     extra_params = [:spam_threshold, :spam_failure_threshold, :postmaster_address]
-    extra_params += [:send_limit, :allow_sender, :log_smtp_data, :outbound_spam_threshold, :message_retention_days, :raw_message_retention_days, :raw_message_retention_size] if current_user.admin?
+    extra_params += [:send_limit, :allow_sender, :privacy_mode, :log_smtp_data, :outbound_spam_threshold, :message_retention_days, :raw_message_retention_days, :raw_message_retention_size] if current_user.admin?
     if @server.update(safe_params(*extra_params))
       redirect_to_with_json organization_server_path(organization, @server), notice: "Server settings have been updated"
     else