Fix garage Wait method not sleeping properly between tries

entrypoint/src/garage/admin_client.go

@@ -130,7 +130,12 @@ func (c *AdminClient) Do(
 // ReplicationFactor-1 other garage instances. If the context is canceled it
 // will return the context error.
 func (c *AdminClient) Wait(ctx context.Context) error {
-	for {
+
+	for first := true; ; first = false {
+
+		if !first {
+			time.Sleep(250 * time.Millisecond)
+		}
 
 		var clusterStatus struct {
 			KnownNodes map[string]struct {
@@ -159,6 +164,5 @@ func (c *AdminClient) Wait(ctx context.Context) error {
 			return nil
 		}
 
-		time.Sleep(250 * time.Millisecond)
 	}
 }