AMMClawback.Asset transaction does not accept XRP currency #3520
Description
The AMMClawback transaction has an asset input field, which does not accept XRP as a valid input. If XRP currency is provided as an input, then the rippled executable should throw a temMALFORMED error. Here is the source code.
The documentation page implies that the asset field accepts XRP as a valid input currency. This contradicts the behavior described by the cpp code.
