Fix unicode literal issue that prevents payment entries to be created (#14515)

diff --git a/erpnext/accounts/utils.py b/erpnext/accounts/utils.py
index 1ff0986..e7ea7e1 100644
--- a/erpnext/accounts/utils.py
+++ b/erpnext/accounts/utils.py
@@ -2,7 +2,7 @@
 # Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
 # License: GNU General Public License v3. See license.txt
 
-
+from __future__ import unicode_literals
 
 import frappe, erpnext
 import frappe.defaults