https://stackoverflow.com/questions/32425547/okhttp-unable-to-find-acceptable-protocolsandroid/45853669#45853669

https://superuser.com/questions/97201/how-to-save-a-remote-server-ssl-certificate-locally-as-a-file

https://gist.github.com/nowke/75037c42171d9ea5ce87a49a982c4c39

 I/System.out: ca=CN=biz.kt.com, OU=Unified Communications, OU="Hosted by Korea Information Certificate Authority, Inc.", OU=IT, O=KT Corporation, STREET="90, Buljeong-ro", L="Bundang-gu, Seongnam-si", ST=Gyeonggi-do, OID.2.5.4.17=13606, C=KR