explicitly disallow SSLv2/v3 to be used since theyr'e deprecated.
TLSv1.2 is the de-facto standard which is widely used those days, so we need to be able to support it.
This change will also allow TLSv1.1, and might allow newer protocols like TLSv1.3 at the future, when they will be added to OpenSSL.
ref: https://www.openssl.org/docs/man1.0.2/ssl/SSL_CTX_new.html
explicitly disallow SSLv2/v3 to be used since theyr'e deprecated.
TLSv1.2 is the de-facto standard which is widely used those days, so we need to be able to support it. This change will also allow TLSv1.1, and might allow newer protocols like TLSv1.3 at the future, when they will be added to OpenSSL. ref: https://www.openssl.org/docs/man1.0.2/ssl/SSL_CTX_new.html