capture: do not start a goroutine on each node event
capture: do not start a goroutine on each node event

This patch moves the goroutine creation to only create
goroutine when sending WS message.

Change-Id: Iffbbef868563714c2e2e92c337d6c0a555edf4df
Reviewed-on: https://softwarefactory-project.io/r/7197
Reviewed-by: Sylvain Baubeau <b0a7dc08a3f38d713e107103b0a85b0badc14b84@redhat.com>
Tested-by: Sylvain Baubeau <b0a7dc08a3f38d713e107103b0a85b0badc14b84@redhat.com>
Workflow: Sylvain Baubeau <b0a7dc08a3f38d713e107103b0a85b0badc14b84@redhat.com>
Tested-by: Jenkins CI <d95b56ce41a2e1ac4cecdd398defd7414407cc08@softwarefactory-project.io>

skydive-project/skydive,safchain/skydive,lebauce/skydive,safchain/skydive,skydive-project/skydive,safchain/skydive,safchain/skydive,lebauce/skydive,safchain/skydive,skydive-project/skydive,skydive-project/skydive,safchain/skydive,lebauce/skydive,safchain/skydive,safchain/skydive,lebauce/skydive,skydive-project/skydive,skydive-project/skydive,lebauce/skydive,lebauce/skydive,skydive-project/skydive,lebauce/skydive,lebauce/skydive