fix(regional): remove duplicate validation for GSTIN
diff --git a/erpnext/regional/india/utils.py b/erpnext/regional/india/utils.py
index 43ed868..d93ef3b 100644
--- a/erpnext/regional/india/utils.py
+++ b/erpnext/regional/india/utils.py
@@ -11,7 +11,7 @@
 	if not hasattr(doc, 'gstin') or not doc.gstin:
 		return
 
-	doc.gstin = doc.gstin.upper().strip() if doc.gstin else ""
+	doc.gstin = doc.gstin.upper().strip()
 	if not doc.gstin or doc.gstin == 'NA':
 		return