standardize deploy.py code to follow fdroidserver patterns
These are small refactoring of recently merged code to make it fit into the existing patterns used in fdroidserver.
- rclone_config always as list to avoid code duplication
- fdroidserver uses lists of strings to handle the escaping command line arguments, this converts the rclone code to that pattern.
@pmmayero could you check to make sure I didn't break your logic?