cmake: reflect changes with CURL_USE_OPENLDAP

The commit "cmake: improve OpenLDAP builds" [1][2] in Curl deletes CMake
option CURL_USE_OPENLDAP.

The patch reflects this change in Tarantool's build infrastructure.

1. https://github.com/curl/curl/commit/751e168d93b4a58f3fbbe2908c0041ae2f934329
2. https://github.com/curl/curl/pull/12024

Follows up #9086

NO_CHANGELOG=third_party
NO_DOC=third_party
NO_TEST=third_party