ctxt_handle is moved to the top of struct tlsw_session so that it can be easily retrieved via LDAP_OPT_X_TLS_SSL_CTX.
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54727
-- v3: wldap32: Implement setting LDAP_OPT_SERVER_CERTIFICATE and add tests. wldap32: Implement ldap_connect.