Validate workers options on standalone mode

[mururu]

No description provided.

[repeatedly]

Which configuation cause this error?

[mururu]

I assume this kind of situation.

$ cat worker.conf
<system>
  workers 3
</system>

$ bundle exec bin/fluentd -c worker.conf --no-supervisor
2017-05-22 17:23:49 +0900 [info]: reading config file path="worker.conf"
bundler: failed to load command: bin/fluentd (bin/fluentd)
Fluent::ConfigError: invalid number of workers (must be 1 or unspecified) on standalone mode
  /Users/yito/ruby/fluentd/lib/fluent/supervisor.rb:494:in `run_worker'
  /Users/yito/ruby/fluentd/lib/fluent/command/fluentd.rb:316:in `<top (required)>'
  bin/fluentd:5:in `require'
  bin/fluentd:5:in `<top (required)>'

[repeatedly]

Okay!