Allow "initdb.d" scripts to be executed instead of sourced

10/alpine/docker-entrypoint.sh

10/docker-entrypoint.sh

11/alpine/docker-entrypoint.sh

11/docker-entrypoint.sh

9.3/alpine/docker-entrypoint.sh

9.3/docker-entrypoint.sh

9.4/alpine/docker-entrypoint.sh

9.4/docker-entrypoint.sh

9.5/alpine/docker-entrypoint.sh

9.5/docker-entrypoint.sh

9.6/alpine/docker-entrypoint.sh

9.6/docker-entrypoint.sh

docker-entrypoint.sh