Remove multi-domain support on admin user pages

refs #166

config/routes.rb

@@ -73,9 +73,14 @@ Rails.application.routes.draw do
   namespace :admin do
     root to: 'dashboard#index'
 
-    resources 'users', param: 'address', only: ['index', 'show'], constraints: { address: /.*/ }
+    resources 'users', param: 'username', only: ['index', 'show'] do
+
+    end
+
     get 'invitations', to: 'invitations#index'
+
     resources :donations
+
     get 'lightning', to: 'lightning#index'
 
     namespace :app_catalog do