Merge pull request #3592 from Xenograph/master

FIX: Substrings of reserved usernames no longer treated as reserved

app/controllers/users_controller.rb

@@ -231,7 +231,7 @@ class UsersController < ApplicationController
       return fail_with("login.password_too_long")
     end
 
-    if SiteSetting.reserved_usernames.include? params[:username].downcase
+    if SiteSetting.reserved_usernames.split("|").include? params[:username].downcase
       return fail_with("login.reserved_username")
     end