fix else condition (#13295)

diff --git a/erpnext/selling/doctype/sales_order/sales_order.js b/erpnext/selling/doctype/sales_order/sales_order.js
index 03e519a..f77a6ad 100644
--- a/erpnext/selling/doctype/sales_order/sales_order.js
+++ b/erpnext/selling/doctype/sales_order/sales_order.js
@@ -53,7 +53,7 @@
 		if (frm.doc.delivery_date) {
 			row.delivery_date = frm.doc.delivery_date;
 			refresh_field("delivery_date", cdn, "items");
-		} else {
+		} else if((frm.doc.items || []).length > 1) {
 			this.frm.script_manager.copy_from_first_row("items", row, ["delivery_date"]);
 		}
 	},