fix(server): remove misleading "Agent not available" warning.

Signed-off-by: Deluan <deluan@navidrome.org>

core/agents/agents.go

@@ -24,15 +24,23 @@ func New(ds model.DataStore) *Agents {
 	}
 	order = append(order, LocalAgentName)
 	var res []Interface
+	var enabled []string
 	for _, name := range order {
 		init, ok := Map[name]
 		if !ok {
-			log.Error("Agent not available. Check configuration", "name", name)
+			log.Error("Invalid agent. Check `Agents` configuration", "name", name, "conf", conf.Server.Agents)
 			continue
 		}
 
+		agent := init(ds)
+		if agent == nil {
+			log.Debug("Agent not available. Missing configuration?", "name", name)
+			continue
+		}
+		enabled = append(enabled, name)
 		res = append(res, init(ds))
 	}
+	log.Debug("List of agents enabled", "names", enabled)
 
 	return &Agents{ds: ds, agents: res}
 }