lnrpc/invoicesrpc: only try to add hop hints if we have channels

lnrpc/invoicesrpc/addinvoice.go

@@ -255,6 +255,7 @@ func AddInvoice(ctx context.Context, cfg *AddInvoiceConfig,
 			return nil, nil, fmt.Errorf("could not fetch all channels")
 		}
 
+		if len(openChannels) > 0 {
 			// We'll restrict the number of individual route hints
 			// to 20 to avoid creating overly large invoices.
 			const numMaxHophints = 20
@@ -264,6 +265,7 @@ func AddInvoice(ctx context.Context, cfg *AddInvoiceConfig,
 
 			options = append(options, hopHints...)
 		}
+	}
 
 	// Set our desired invoice features and add them to our list of options.
 	invoiceFeatures := cfg.GenInvoiceFeatures()