Fix accidental translations join

We added the code thinking we were ordering by the name of the poll, but
here we're actually ordering by the name of the booth.

app/models/poll/booth.rb

@@ -12,7 +12,7 @@ class Poll
     end
 
     def self.available
-      where(polls: { id: Poll.current_or_recounting }).joins(polls: :translations)
+      where(polls: { id: Poll.current_or_recounting }).joins(:polls)
     end
 
     def assignment_on_poll(poll)