bugfix: undefined symbol SSL_client_hello_get0_ext when linking again…

[zhuizhuhaomeng]

…st libressl.

I hereby granted the copyright of the changes in this pull request to the authors of this lua-nginx-module project.

[zhuizhuhaomeng]

please try again

[asyslinux]

nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful