Show debug level at startup

I think it is efficient to also show the debug level at the startup. To verify that indeed the correct settings of the debuglevel started correctly. Especially when trying to capture rare bugs.

lnd.go

@@ -200,9 +200,9 @@ func Main(cfg *Config, lisCfg ListenerCfg, shutdownChan <-chan struct{}) error {
 	}()
 
 	// Show version at startup.
-	ltndLog.Infof("Version: %s commit=%s, build=%s, logging=%s",
+	ltndLog.Infof("Version: %s commit=%s, build=%s, logging=%s debuglevel=%s",
 		build.Version(), build.Commit, build.Deployment,
-		build.LoggingType)
+		build.LoggingType, cfg.DebugLevel)
 
 	var network string
 	switch {