vmagent: fix consul target address relabel (#516)

The consul job joins node and port with ":" but then sets `replacement: "${1}:${2}"` with the default `(.*)` regex, so `__address__` becomes `node:port:`. vmagent rejects every consul target as an invalid port, including node_exporter.

- drop the replacement so the default `$1` yields `node:port`

Reviewed-on: #516
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>

apps/base/observability/vmagent.yaml

@@ -120,7 +120,6 @@ spec:
         - source_labels: [__meta_consul_node, __meta_consul_service_port]
           separator: ":"
           target_label: __address__
-          replacement: "${1}:${2}"
           action: replace
         - source_labels: [__meta_consul_tag_metrics_scheme]
           target_label: __scheme__