Fix poller affecting Sidekiq scheduled set poller (#359)

Avoid setting global config so that we do not change the behavior of the
Sidekiq scheduled set poller.

Closes #358

lib/sidekiq/cron/launcher.rb

@@ -13,7 +13,7 @@ module Launcher
 
       # Add cron poller and execute normal initialize of Sidekiq launcher.
       def initialize(options)
-        @cron_poller = Sidekiq::Cron::Poller.new
+        @cron_poller = Sidekiq::Cron::Poller.new(options)
         super(options)
       end
 

lib/sidekiq/cron/poller.rb

@@ -5,20 +5,17 @@
 
 module Sidekiq
   module Cron
-    POLL_INTERVAL = Sidekiq::Options[:average_scheduled_poll_interval] || 30
+    POLL_INTERVAL = 30
 
     # The Poller checks Redis every N seconds for sheduled cron jobs.
     class Poller < Sidekiq::Scheduled::Poller
-      def initialize
-        Sidekiq.configure_server do
-          Sidekiq::Options[:poll_interval_average] = POLL_INTERVAL
-        end
-
+      def initialize(options = {})
         if Gem::Version.new(Sidekiq::VERSION) >= Gem::Version.new('6.5.0')
-          # Sidekiq Poller init requires a config argument.
-          super(Sidekiq)
-        else
           super
+        else
+          # Old version of Sidekiq does not accept a config argument.
+          @config = options
+          super()
         end
       end
 
@@ -45,6 +42,10 @@ def enqueue_job(job, time = Time.now.utc)
         Sidekiq.logger.error "CRON JOB: #{ex.backtrace.first}"
         handle_exception(ex) if respond_to?(:handle_exception)
       end
+
+      def poll_interval_average
+        @config[:average_scheduled_poll_interval] || POLL_INTERVAL
+      end
     end
   end
 end