FEATURE: only allow sidekiq in master site when hosted on multisite

lib/admin_constraint.rb

@@ -2,7 +2,12 @@ require_dependency 'current_user'
 
 class AdminConstraint
 
+  def initialize(options={})
+    @require_master = options[:require_master]
+  end
+
   def matches?(request)
+    return false if @require_master && RailsMultisite::ConnectionManagement.current_db != "default"
     provider = Discourse.current_user_provider.new(request.env)
     provider.current_user && provider.current_user.admin?
   end