After enabling arch repos, need to download database files. Otherwise, calls to
`pacman -S` return errors that are suppressed by redirection to /dev/null.
Error Message:
```sh
warning: database file for 'extra' does not exist (use "-Sy" to download)
error: failed to prepare transcation (could not find database)
```
Fixes: https://github.com/LukeSmithxyz/LARBS/issues/393
