fix: Use block variable

Co-authored-by: Deepesh Garg <deepeshgarg6@gmail.com>
diff --git a/erpnext/selling/doctype/quotation/quotation.js b/erpnext/selling/doctype/quotation/quotation.js
index f77dce8..81ef44d 100644
--- a/erpnext/selling/doctype/quotation/quotation.js
+++ b/erpnext/selling/doctype/quotation/quotation.js
@@ -236,7 +236,7 @@
 	}
 
 	show_alternative_items_dialog() {
-		var me = this;
+		let me = this;
 
 		const table_fields = [
 		{