Use .presence for queue_name_prefix in mailer_queue_name

Match ActiveJob's own queue name composition by using .presence
instead of bare value, preventing a leading delimiter when the
prefix is an empty string.

Author: adis-io

lib/advanced_sneakers_activejob/workers_registry.rb

@@ -104,7 +104,7 @@ def advanced_sneakers_adapter?(klass)
     # Queue name from ActionMailer::Base.deliver_later_queue_name is not prefixed
     # and has no delimiter, so we need to add them manually
     def mailer_queue_name(mailer)
-      [ActiveJob::Base.queue_name_prefix, mailer.deliver_later_queue_name.to_s].compact.join(ActiveJob::Base.queue_name_delimiter)
+      [ActiveJob::Base.queue_name_prefix.presence, mailer.deliver_later_queue_name.to_s].compact.join(ActiveJob::Base.queue_name_delimiter)
     end
   end
 end