update Str_trunc unit test
update Str_trunc unit test

ClearwaterCore/clearwater-monit,GaiaMagic/monit,GaiaMagic/monit,GaiaMagic/monit,Metaswitch/clearwater-monit,kemadz/monit,Metaswitch/clearwater-monit,kemadz/monit,kemadz/monit,Metaswitch/clearwater-monit,ClearwaterCore/clearwater-monit,ClearwaterCore/clearwater-monit