Fix pmbootstrap-on-postmarketOS

@minlexx encountered this issue:

pinetab:~$ pmbootstrap init
[01:30:33] Location of the 'work' path. Multiple chroots (native, device arch, device rootfs) will be created in there.
[01:30:33] Work path [/home/user/.local/var/pmbootstrap]: 
[01:30:35] pmbootstrap does everything in Alpine Linux chroots, so your host system does not get modified. In order to work with these chroots, pmbootstrap calls 'sudo' internally. To see the commands it runs, you can run 'pmbootstrap log' in a second terminal.
[01:30:35] Setting up the native chroot and cloning the package build recipes (pmaports)...
[01:30:35] Update package index for aarch64 (4 file(s))
[01:30:41] Download http://dl-cdn.alpinelinux.org/alpine/edge/main/aarch64/apk-tools-static-2.10.4-r3.apk
[01:30:42] ERROR: Failed to validate signature of apk.static. Either openssl is not installed, or the download failed. Run 'pmbootstrap zap -hc' to delete the download and try again.
[01:30:42] See also: <https://postmarketos.org/troubleshooting>
Run 'pmbootstrap log' for details.

I had an issue after this step on the parts where it created chroots, but don't have a log handy for it.