--generate-completion now exits with 1

[wbouvy]

It calls

throw PrintCompletionMessage(message)

which is a PrintMessage

class PrintCompletionMessage(message: String) : PrintMessage(message)

which now defaults to exit code 1 for some reason, even if error is false?

open class PrintMessage(
    message: String,
    statusCode: Int = 1,
    printError: Boolean = false,
) : CliktError(message, statusCode = statusCode, printError = printError)

[wbouvy]

I'd be happy to submit a PR changing the default to 0, but I'm not sure what all the side effects would be, so I figured I'd make an issue first :)