made sender address in notifier.rb configurable. This fixes #657

app/mailers/notifier.rb

@@ -1,6 +1,6 @@
 class Notifier < ActionMailer::Base
   
-  default :from => "no-reply@joindiaspora.com"
+  default :from => APP_CONFIG[:smtp_sender_address]
   
   ATTACHMENT = File.read("#{Rails.root}/public/images/diaspora_white_on_grey.png")
 

config/app_config.yml.example

@@ -54,7 +54,7 @@ default:
   smtp_domain: 'example.com'
 
   # Sender address in diaspora's outgoing mail.
-  smtp_sender_address: 'no-reply@example.com'
+  smtp_sender_address: 'no-reply@joindiaspora.com'
 
   # Authentication required to send mail. Use one of 'one','plain',
   # 'login' or 'cram-md5'. Use 'none' if server do not support