Add defensive check to AfterUnallowDomainService (#37744)

Co-authored-by: Your Name <you@example.com>

app/services/after_unallow_domain_service.rb

@@ -2,7 +2,9 @@
 
 class AfterUnallowDomainService < BaseService
   def call(domain)
-    Account.where(domain: domain).find_each do |account|
+    return if domain.blank?
+
+    Account.remote.where(domain: domain).find_each do |account|
       DeleteAccountService.new.call(account, reserve_username: false)
     end
   end