Fix the retry attempts number when no option is defined.

Fix the PR https://github.com/swarrot/SwarrotBundle/pull/28
you can remove ``$input->hasOption('retry-attempts')`` entirely as it will always be true. the option is added based on ``array_key_exists('retry', $this->processorStack)``, and this code is inside a ``array_key_exists('retry', $this->processorStack)`` condition