Fix ubuntu 21.10 build

[ChrisMacGregor]

This is a minimal set of changes to get the build to work on Ubuntu 21.10, which (based on the numerous posts, issues, questions, etc. that I found in the course of figuring out how to get this to build) would apparently save a lot of people a lot of trouble. The MicroPython ESP8266 port points to your repo, so anyone trying to follow those instructions is going to run into these same problems.