Restrict permissions on Postgres backups files. Resolves #322.

roles/tarsnap/files/tarsnap.sh

@@ -58,6 +58,7 @@ fi
 cd /home/
 
 # Dump PostgreSQL to file
+umask 077
 sudo -u postgres pg_dumpall -c | gzip > /decrypted/postgresql-backup.sql.gz
 
 # Do backups