3 * LDK previously serialized `PaymentRelay::fee_base_msat` as a u32 when it
4 should have been serialized as a tu32. Similarly, we were serializing
5 `PaymentConstraints::htlc_minimum_msat` as a u64 when we should have been
6 serializing it as tu64. This caused lack of interoperability when using other
7 implementations as forwarding nodes along blinded payment paths.