Fixed reference to @service.request_timeout to @request_timeout. 

This was raising an error with the following details:

    ERROR : Error running task in Agent Worker Loop 'undefined method `request_timeout' for nil:NilClass': /apps/crm/shared/bundle/ruby/1.9.1/gems/newrelic_rpm-3.4.0/lib/new_relic/agent/new_relic_service.rb:170:in `rescue in send_request'

I believe the reference to @service should be referencing self.