Fix my merge of d5c3403.

I think when I merged this, I let a new pidfile task slip
in. It shouldn't be there.

Fixes resque#710
Fixes resque#715

Author: steveklabnik

lib/resque/tasks.rb

@@ -5,7 +5,7 @@
   task :setup
 
   desc "Start a Resque worker"
-  task :work => [:pidfile, :setup] do
+  task :work => :setup do
     require 'resque'
 
     queues = (ENV['QUEUES'] || ENV['QUEUE']).to_s.split(',')