Update sales_invoice.py

[fixes] pulling available qty on selection of item in case of pos
diff --git a/accounts/doctype/sales_invoice/sales_invoice.py b/accounts/doctype/sales_invoice/sales_invoice.py
index 6871b1e..ab44247 100644
--- a/accounts/doctype/sales_invoice/sales_invoice.py
+++ b/accounts/doctype/sales_invoice/sales_invoice.py
@@ -351,7 +351,7 @@
 			
 			if ret.get("warehouse"):
 				ret["actual_qty"] = flt(webnotes.conn.get_value("Bin",
-					{"item_code": args.get("item_code"), "warehouse": args.get("warehouse")},
+					{"item_code": args.get("item_code"), "warehouse": ret.get("warehouse")},
 					"actual_qty"))
 		return ret