[CMD] kamel bind empty error handler

[squakez]

I think the test spotted an hidden issue:

=== RUN   TestKamelCLIBind/bind_timer_to_log
KameletBinding.camel.apache.org "test-timer-source-to-log" is invalid: []: Invalid value: map[string]interface {}{"kind":"KameletBinding", "apiVersion":"camel.apache.org/v1alpha1", "metadata":map[string]interface {}{"uid":"2948e0fe-e2f1-11eb-b545-000d3a02688e", "selfLink":"", "clusterName":"", "name":"test-timer-source-to-log", "namespace":"test-6a95d672-8ac8-4df7-8688-1eacb6220973", "creationTimestamp":"2021-07-12T09:11:37Z", "generation":1}, "spec":map[string]interface {}{"source":map[string]interface {}{"ref":map[string]interface {}{"kind":"Kamelet", "namespace":"test-6a95d672-8ac8-4df7-8688-1eacb6220973", "name":"test-timer-source", "apiVersion":"camel.apache.org/v1alpha1"}, "properties":map[string]interface {}{"message":"helloTest"}}, "sink":map[string]interface {}{"uri":"log:info"}, "errorHandler":interface {}(nil)}}: validation failure list:
spec.errorHandler in body must be of type object: "null"

Probably the bind operation is setting a null error handler, when instead it should be omitted as empty.

Originally posted by @squakez in #2461 (comment)

[squakez]

I am having a look at it. cc @vsokolov00