External signer Send button disabled

When using an external signer, the Create Unsigned button actually signs on the hardware device and the Send button is incorrectly disabled. Probably a regression from #441.

<img width="486" alt="Schermafbeelding 2022-02-18 om 17 27 00" src="https://user-images.githubusercontent.com/10217/154731834-b3371eda-1988-4c2b-b7f0-75440e6c1fe1.png">


cc @achow101 