Refactor admin settings routes

This is much cleaner, and semantically more correct.

app/controllers/admin/settings/registrations_controller.rb

@@ -1,8 +1,8 @@
 class Admin::Settings::RegistrationsController < Admin::SettingsController
-  def index
+  def show
   end
 
-  def create
+  def update
     update_settings
 
     redirect_to admin_settings_registrations_path, flash: {

app/controllers/admin/settings/services_controller.rb

@@ -1,19 +1,32 @@
 class Admin::Settings::ServicesController < Admin::SettingsController
-  def index
-    @service = params[:s]
+  before_action :set_service, only: [:show, :update]
 
-    if @service.blank?
-      redirect_to admin_settings_services_path(params: { s: "btcpay" })
-    end
+  def index
+    redirect_to admin_settings_service_path("btcpay")
   end
 
-  def create
-    service = params.require(:service)
+  def show
+  end
 
+  def update
     update_settings
 
-    redirect_to admin_settings_services_path(params: { s: service }), flash: {
+    redirect_to admin_settings_service_path(@service), flash: {
       success: "Settings saved"
     }
   end
+
+  private
+
+    def set_subsection
+      @subsection = "services"
+    end
+
+    def set_service
+      @service = params[:service]
+
+      if @service.blank?
+        redirect_to admin_settings_services_path and return
+      end
+    end
 end

app/controllers/admin/settings_controller.rb

@@ -20,7 +20,7 @@ class Admin::SettingsController < Admin::BaseController
     end
 
     if @errors.any?
-      render :index and return
+      render :show and return
     end
 
     changed_keys.each do |key|