Use lndhub.go v2 endpoint for invoice creation

app/services/lndhub_manager/create_user_invoice.rb

@@ -1,5 +1,5 @@
 module LndhubManager
-  class CreateUserInvoice < Lndhub
+  class CreateUserInvoice < LndhubV2
     def initialize(user:, payload:)
       @user = user
       @payload = payload
@@ -7,7 +7,7 @@ module LndhubManager
 
     def call
       authenticate @user
-      addinvoice @payload
+      create_invoice @payload
     end
   end
 end