fix: Error on creating invoice

(cherry picked from commit e11515a3561eac6d33d21190cac2db112ae301fb)
diff --git a/erpnext/regional/india/utils.py b/erpnext/regional/india/utils.py
index bbca772..9743c3b 100644
--- a/erpnext/regional/india/utils.py
+++ b/erpnext/regional/india/utils.py
@@ -217,6 +217,7 @@
 		return
 
 	if not party_details.place_of_supply: return party_details
+	if not party_details.company_gstin: return party_details
 
 	if ((doctype in ("Sales Invoice", "Delivery Note", "Sales Order") and party_details.company_gstin
 		and party_details.company_gstin[:2] != party_details.place_of_supply[:2]) or (doctype in ("Purchase Invoice",