Revert most of the cipher suite tweaks.

I'm getting nowhere. I still got an A+, but now I'm marked down because
I don't support TLS 1.2.

snippets/ssl-modern.conf

 # vim: ft=nginx
 include                     snippets/ssl-common.conf;
 ssl_protocols               TLSv1.2 TLSv1.3;
-ssl_ciphers                 HIGH:!NULL:!AES128:!ARIA128:!CAMELLIA:!SHA1:!kRSA:!AES:AESCCM;
+ssl_ciphers                 HIGH:!NULL:!AES128:!ARIA128:!CAMELLIA:!SHA1:!kRSA;