try to migrate from sqlite (origin gitea 1.3.x installation (but fequently updated and running 1.5.0 atm)) to MariaDB
do a fresh gitea installation in a new mariadb database and make a dump
mysqldump -h 127.1 -P 3307 -u root -ppassword --no-data gitea | grep --invert-match -E '\/\*|\--' > filtered_init.ddl