Remove old poll_interval attribute

lib/sidekiq.rb

@@ -153,16 +153,6 @@ def self.logger=(log)
     Sidekiq::Logging.logger = log
   end
 
-  # When set, overrides Sidekiq.options[:average_scheduled_poll_interval] and sets
-  # the average interval that this process will delay before checking for
-  # scheduled jobs or job retries that are ready to run.
-  #
-  # See sidekiq/scheduled.rb for an in-depth explanation of this value
-  def self.poll_interval=(interval)
-    $stderr.puts "DEPRECATION: `config.poll_interval = #{interval}` will be removed in Sidekiq 4. Please update to `config.average_scheduled_poll_interval = #{interval}`."
-    self.options[:poll_interval_average] = interval
-  end
-
   # How frequently Redis should be checked by a random Sidekiq process for
   # scheduled and retriable jobs. Each individual process will take turns by
   # waiting some multiple of this value.

lib/sidekiq/scheduled.rb

@@ -105,7 +105,7 @@ def random_poll_interval
       # all your Sidekiq processes at the same time will lead to them all polling at
       # the same time: the thundering herd problem.
       #
-      # We only do this if poll_interval is unset (the default).
+      # We only do this if poll_interval_average is unset (the default).
       def poll_interval_average
         Sidekiq.options[:poll_interval_average] ||= scaled_poll_interval
       end