Add hook property to control command output logging

[moorereason]

webhook currently logs command output on every request. When using include-command-output-in-response to send a complex response body, it may not be desirable to log the command output. See #676 (comment).

Proposal

Add a boolean disable-command-output-logging property. The default is false so that we're backward compatible.

This property would only affect "success" logging (as seen below). Errors would still be logged.

webhook/webhook.go

Line 624 in dbc6565

log.Printf("[%s] command output: %s\n", r.ID, out)