@Bean
    @ConditionalOnMissingBean(LdapOperations.class)
    public LdapTemplate ldapTemplate(final LdapContextSource ldapContextSource) {
        return new LdapTemplate(ldapContextSource);
    }
register ldap template in spring ioc.

@param ldapContextSource the ldap context source
@return LdapTemplate {@linkplain LdapTemplate}
shenyu-admin/src/main/java/org/apache/shenyu/admin/config/LdapConfiguration.java