rhel6: openldap sever does not work with SSL/TLS after changing SSL/TLS configuration in the config tree

Issue

• openldap sever does not work with SSL/TLS after changing SSL/TLS configuration in the config tree
• openldap sever does not work with SSL/TLS, after olcTLSCertificateFile and olcTLSCertificateKeyFile are changed several times:

# cat /tmp/mod.ldif
dn: cn=config
changetype: modify
replace: olcTLSCertificateFile
olcTLSCertificateFile: /etc/openldap/cert.pem
-
replace: olcTLSCertificateKeyFile
olcTLSCertificateKeyFile: /etc/openldap/cert.key
-
# ldapmodify -x -f /tmp/mod.ldif -D cn=config -w secret
# ldapsearch -x -H ldaps://127.0.0.1 -D "cn=Manager,dc=my-domain,dc=com" -w "secret" -b "dc=my-domain,dc=com" "*"
success
# ldapmodify -x -f /tmp/mod.ldif -D cn=config -w secret
# ldapsearch -x -H ldaps://127.0.0.1 -D "cn=Manager,dc=my-domain,dc=com" -w "secret" -b "dc=my-domain,dc=com" "*"
ldap_sasl_bind(SIMPLE): Can't contact LDAP server (-1)