mark openldap-ltb as a replacement for older openldap-ltb-contrib-ove…

…rlays packages (#91)

openldap-ltb/debian/control

@@ -9,6 +9,7 @@ Homepage: http://ltb-project.org
 Package: openldap-ltb
 Architecture: any
 Depends: libc6 (>= 2.4), libltdl7, libsasl2-2, libwrap0 (>= 7.6-4~), coreutils (>= 4.5.1-1), perl (>> 5.8.0) | libmime-base64-perl, adduser, lsb-base (>= 3.2-13), openssl, bash-completion, procps, libevent-2.1-6 | libevent-2.1-7, libsodium23
+Replaces: openldap-ltb-contrib-overlays (<< 2.5.13)
 Suggests: openldap-ltb-mdb-utils, openldap-ltb-contrib-overlays
 Description: OpenLDAP server with addons from the LDAP Tool Box project
  OpenLDAP is an open source suite of LDAP (Lightweight Directory Access