main/postmarketos-android-recovery-installer: upgrade to 1.0.4
Fix crash if /etc/skel is missing.
This is a trivial shell script change, I did not verify that it works, but I'm confident that it does:
Based on a similar patch in pmbootstrap:
https://gitlab.com/postmarketOS/pmbootstrap/-/merge_requests/2001/diffs
Fixes: https://gitlab.com/postmarketOS/postmarketos-android-recovery-installer/-/issues/8