Never mind. They were on my SMTP servers. I'm setting up a multi-server install and I was looking for them on my LDAP server.
[zimbra@zsmtp0 ~]$ ls /opt/zimbra/conf/ldap*
/opt/zimbra/conf/ldap-scm.cf /opt/zimbra/conf/ldap-vam.cf
/opt/zimbra/conf/ldap-transport.cf /opt/zimbra/conf/ldap-vmd.cf
/opt/zimbra/conf/ldap-vad.cf /opt/zimbra/conf/ldap-vmm.cf
[zimbra@zsmtp0 ~]$
Here's how I applied the fix:
for x in ldap-scm.cf ldap-transport.cf ldap-vad.cf ldap-vam.cf ldap-vmd.cf ldap-vmd.cf;
do
cp $x $x.bak;
sed -i s/"start_tls =yes"/"start_tls = no"/g $x;
done