Make no order notes label more generic

To account for it being displayed on custom order type Add/Edit screens
where the order type is not referred to as an 'Order' (e.g. a 'Subscription',
'Refund' or 'Pre-order').

includes/admin/meta-boxes/class-wc-meta-box-order-notes.php

@@ -58,7 +58,7 @@ class WC_Meta_Box_Order_Notes {
 			}
 
 		} else {
-			echo '<li>' . __( 'There are no notes for this order yet.', 'woocommerce' ) . '</li>';
+			echo '<li>' . __( 'There are no notes yet.', 'woocommerce' ) . '</li>';
 		}
 
 		echo '</ul>';