correcting message type for the outstanding invoice type (#1336)

Author: saravanpa-aot

queue_services/account-mailer/src/account_mailer/enums.py

@@ -31,7 +31,7 @@ class MessageType(Enum):
     ONLINE_BANKING_UNDER_PAYMENT = 'bc.registry.payment.UnderPaid'
     ONLINE_BANKING_PAYMENT = 'bc.registry.payment.Payment'
     PAD_SETUP_FAILED = 'bc.registry.payment.PadSetupFailed'
-    PAYMENT_PENDING = 'bc.registry.payment.paymentPending'
+    PAYMENT_PENDING = 'bc.registry.payment.ob.outstandingInvoice'
 
 
 class SubjectType(Enum):