JSON Parser implementation and documentation mismatch

[taraspos]

Hello, I faced unexpected behavior from fluentd JSON parser, because of the parse documentation and actual implementation of JSON parser differs.

Long story short, fluentd picked event time from json key time, when I expected it to use the current time:

Documentation says:

time_key (string) (optional): Specify time field for event time. If the event doesn’t have this field, current time is used.

• Default: nil

Implementation says:

config_set_default :time_key, 'time'

[fujimotos]

The documentation has been fixed by #597. Thanks for pointing out the flaw.