entrypoint: Run apk update before upgrade
We can get into situations where apk upgrade fails consistently with
WARNING: opening /home/builder/packages/main: No such file or directory
WARNING: opening /home/builder/packages/community: No such file or directory
WARNING: opening /home/builder/packages/testing: No such file or directory
ERROR: Not continuing due to stale/unavailable repositories.Use --force-missing-repositories to continue.
Signed-off-by: Khem Raj raj.khem@gmail.com
Edited by Kevin Daudt