make release names package files with libbeat version rather than beat version

[chris-counteractive]

The packages generated during make release are labeled with the libbeat version (lately, 7.4.0) rather than the beat version (lately, 1.4.1). The version in the actual beat itself, that makes it into the event metadata, is correct. I think this has to do with how environment variables are (or are not) passed to the docker containers used in the build process, but for now I've just been renaming the packages before upload with something like

for f in o365beat-7.4.0-*; do mv "$f" "$(echo "$f" | sed s/7\.4\.0/1\.4\.1/)"; done

Low priority, but worth fixing at some point.