Fix syntax in #681 by referencing #831

[ligi]

as correctly brought up by @maciejhirsz here (#681 (comment)) and just discussed with @nagydani - referencing #831 in the syntax part of #681

[axic]

@nagydani can you approve this?

[axic]

@ligi btw, the motivation section has

This specification supersedes ERC #67

I think it would make sense including a replaces: 67 header.

[ligi]

@axic thanks - good idea - I think a replaces: header would make sense here. Will open a PR for this after we merged this one. I will see @nagydani most likely this week so I think we can get this merged ,-)

[nagydani]

Perfectly reasonable.

[nagydani]

@ligi btw, the motivation section has

This specification supersedes ERC #67

I think it would make sense including a replaces: 67 header.

We did have that header and it was removed because EIP 67 has, in fact, never been accepted.