Revert "stage2: Add apt-transport-https" (RPi-Distro#304)

This reverts commit 1806504.

In Buster, APT has built‐in support for HTTPS repos (since version 1.5).
The ca-certificates package is already included in the modified file, so
this commit shouldn’t break anything.

stage2/01-sys-tweaks/00-packages

@@ -18,7 +18,6 @@ exfat-fuse
 ntfs-3g
 hfsplus hfsutils hfsprogs
 usbmount
-apt-transport-https
 libpam-chksshpwd
 rpi-update
 libmtp-runtime