Doc: Kafka input default values are not coherent

[psanz-estc]

This statement from kafka input documentation is not aligned with our default values:

The value of the configuration request_timeout_ms must always be larger than max_poll_interval_ms

Default values:

max_poll_interval_ms -> Default value is 300000 milliseconds (5 minutes)

request_timeout_ms -> Default value is 40000 milliseconds (40 seconds).

Following our default values, request_timeout_ms is smaller than max_poll_interval_ms

Documentation should be fixed.

[robbavey]

Closing as a dupe of this issue in the kafka plugin repo.