Windows Events Plugin: custom_channels required parameter even if enable_custom_channels is set to false

[nemerkab]

When configuring the windows_events plugin, the parameter for custom_channels is always required even if enable_custom_channels has been set to false. I expect custom_channels to not be required in that situation.

If the custom_channels parameter must be required, then additional documentation to explain what should be provided in that parameter when you do not want to use custom channels would be helpful. I am referring to the documentation found here: https://github.com/observIQ/stanza/blob/master/docs/examples/scenarios/windows_events.md