Ignore SSL_R_SHORT_READ

We received SSL_R_SHORT_READ on a few SSL hosts. We learned that this is error can be ignored and everything works well. See i.e. https://sourceforge.net/p/asio/mailman/message/29297653/ https://github.com/boostorg/beast/issues/38

You may replace the define by a better native reference - i did not find it in your code.

Best regards