Ignore decode message part with content-type message/rfc822
Ignore decode message part with content-type message/rfc822

According to https://tools.ietf.org/html/rfc2046#section-5.2.1
no encoding other than 7bit, 8bit or binary is allowed for
message/rfc822 part. If the email provide the transfer-encoding
then it should be ignored or no decode.

cention-sany/go.enmime