CR-1829 OPENDJ-982 Upgrade: SNMP Connection Handler does not start after the upgrade
As suggested in CR, a new upgrade task has been created 'Rename SNMP security config file'. This task is launched if the old SNMP config file
actually exists in the config/snmp/security.
The task renames the file with the new opendj name.

NOTA : The config/snmp/security/opends-snmp.security has been changed in 2.5.0.7466 and the community name as well. ( Cf. Matt's comment in CR).