Workaround for type change in tommath

[mborland]

Closes: #602

@jzmaddock This is certainly not the most robust solution on earth, but I see that we check against similar deprecation macros elsewhere. They have no versioning macro so I can't think of a better solution.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 94.1%. Comparing base (3c9ff4d) to head (5675c50).

Additional details and impacted files

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[jzmaddock]

Thanks Matt, this is about all we can do here I think.