(Reading database ... 31493 files and directories currently installed.)
Preparing to unpack .../base-files-osmc_2.4.5_all.deb ...e free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.
Your copy/paste looks to be borked.
Update. I’ve had a chance to look at the code on base-files-osmc. Unfortunately, it has this check:
# migrate sources.list only if the previous base-files-osmc version is older than this version
if [ -n "$2" ] && dpkg --compare-versions "$2" lt "2.4.5"; then
dist_upgrade_migrate
fi
which means that --reinstall won’t work. Nice one!
So, just edit /etc/apt/sources.list and change every occurrence of jessie to stretch. Then, once again:
sudo apt-get update
sudo apt-get dist-upgrade
