unify sftp config file

vs_starter/templates/docker-compose.yml

@@ -172,14 +172,14 @@ services:
         source: from-fepd
         target: /home/eox/data/from/fepd
     configs:
-      - source: sftp_users_{{slug}}
+      - source: sftp_users_pass
         target: /etc/sftp/users.conf
     ports:
       - "{{sftp}}:22"
     deploy:
       replicas: 1
 configs:
-  sftp_users_{{slug}}:
+  sftp_users_pass:
     external: true
   init-db:
     file: ./config/init-db.sh