CI package build: don't buffer output and silent "git fetch"
This disables Python's output buffering, which caused the text of build_changed_aports.py (which commits it's looking at, what will be built etc.) appear after the output from building the package.
Also I've added -q to the git fetch line, so it does not print out the branches from the upstream repository.
New output for a failed package:
Previous output (except for the empty lines, but the important part is that the text block starting with "commit HEAD" is at the bottom, not at the top of the build):