debian/postinst: make sure all dirs exist
debian/postinst: make sure all dirs exist


Former-commit-id: f504c88dadfe381f44e5cd2d4d858ea0d4b70d77 [formerly f504c88dadfe381f44e5cd2d4d858ea0d4b70d77 [formerly fb23d1aff64b3566390cce80b059f50c2f717330]]
Former-commit-id: acf45adf974a6445b331147582fce407f48e9ca7
Former-commit-id: d6b131f9f83ae7dd554950312b8bfe13ad1a37dc
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine