Remove ln_login from users

Not needed anymore, removing in favor of unencrypted `ln_account`.

app/jobs/create_lndhub_account_job.rb

@@ -2,13 +2,12 @@ class CreateLndhubAccountJob < ApplicationJob
   queue_as :default
 
   def perform(user)
-    return if user.ln_login.present? && user.ln_password.present?
+    return if user.ln_account.present? && user.ln_password.present?
 
     lndhub = LndhubV2.new
     credentials = lndhub.create_account
 
     user.update! ln_account: credentials["login"],
-                 ln_login: credentials["login"], # TODO remove when production is migrated
                  ln_password: credentials["password"]
   end
 end