Do not try to push metrics to local Fluentbit if not installed

This should prevent the following from happening in the MONIT clusters
that push metrics directly from Prometheus to MoM without any
Fluentbit in between:

ts=2025-02-14T11:37:32.111Z caller=dedupe.go:112 component=remote
level=warn remote_name=6c01d0
url=http://it-monit-metrics-fluentbit:8080/api/prom/push msg="Failed
to send batch, retrying" err="Post
\"http://it-monit-metrics-fluentbit:8080/api/prom/push\": dial tcp:
lookup it-monit-metrics-fluentbit on 10.254.0.10:53: no such host"