Fixed issue with user list (#589)

app/controllers/admins_controller.rb

@@ -170,12 +170,14 @@ class AdminsController < ApplicationController
 
   # Gets the list of users based on your configuration
   def user_list
-    list = if @role.present?
-      User.with_role(@role.to_sym).where.not(id: current_user.id)
-    else
+    initial_list = if current_user.has_role? :super_admin
       User.where.not(id: current_user.id)
+    else
+      User.without_role(:super_admin).where.not(id: current_user.id)
     end
 
+    list = @role.present? ? initial_list.with_role(@role.to_sym) : initial_list
+
     if Rails.configuration.loadbalanced_configuration
       list.where(provider: user_settings_provider)
           .admins_search(@search)