Fix detecting changed aports
How it would look like when postmarketOS/pmaports has a broken commit: https://gitlab.com/z3ntu/pmaports/-/jobs/101107555
How it would look like a fork (e.g. z3ntu/pmaports) has a broken commit somewhere between upstream/master and HEAD: https://gitlab.com/z3ntu/pmaports/-/jobs/101108097
Fixes #27 (closed)