"interval" should not be required in logstash-input-exec plugin

Elastic Stack Logstash
1

Logstash Version : 5.3.0

"interval" setting is now required in logstash-input-exec plugin.
When I want to execute some command only once, I have to set interval.

Interval should be optional and the default should be "execute once".

2

Could you file an issue at https://github.com/logstash-plugins/logstash-input-exec/issues/new?