setting esm-class

Hi,
I am running the following version of kannel
   Kannel bearerbox version `1.5.0'. Build `Dec 25 2010 11:25:25',
   compiler `4.4.5'. System Linux, release 3.2.0-30-virtual, version
   #48-Ubuntu SMP Fri Aug 24 17:34:24 UTC 2012, machine i686. Hostname
   ip-10-248-101-18, IP 127.0.0.1. Libxml version 2.7.8. Using OpenSSL
   0.9.8o 01 Jun 2010. Compiled with MySQL 5.1.49, using MySQL 5.1.70.
   Using SQLite 3.7.3. Using native malloc.

I have tried to set the esm-class in kannel.conf with no success. I keep
getting the following error
ERROR: Group 'smsc' may not contain field 'esm-class'

My provider requires I set esm class to 0. I have read about patching the
smsc_smpp.c on line: pdu->u.submit_sm.esm_class =
ESM_CLASS_SUBMIT_STORE_AND_
FORWARD_MODE
to pdu->u.submit_sm.esm_class = ESM_CLASS_SUBMIT_DEFAULT_SMSC_MODE

but I am unable to locate the file. The post is old so maybe the file name
has changed. Can someone tell me where I can locate it please.


-- 
Regards,
Eric Magutu