[minor] Code cleanup (#12278)

diff --git a/erpnext/regional/united_arab_emirates/utils.py b/erpnext/regional/united_arab_emirates/utils.py
index 3ba2030..61ffadb 100644
--- a/erpnext/regional/united_arab_emirates/utils.py
+++ b/erpnext/regional/united_arab_emirates/utils.py
@@ -7,7 +7,9 @@
 	itemised_tax = get_itemised_tax(doc.taxes)
 
 	for row in doc.items:
-		tax_rate = sum([tax.get('tax_rate', 0) for d, tax in itemised_tax.get(row.item_code).items()])
+		tax_rate = 0.0
+		if itemised_tax.get(row.item_code):
+			tax_rate = sum([tax.get('tax_rate', 0) for d, tax in itemised_tax.get(row.item_code).items()])
 
 		row.tax_rate = flt(tax_rate, row.precision("tax_rate"))
 		row.tax_amount = flt((row.net_amount * tax_rate) / 100, row.precision("net_amount"))