Specifying a full profile in `dl_dep.sh` with `-d` does not work

Specifying the download of a dependency with the long form does not always work. For example:

$ /scripts/dl_dep.sh -d rocksdb@mogon2:latest /tmp/foo

Ends up downloading the rocksdb dependency from the default profile, instead of giving an error since rocksdb is not defined in the mogon2 profile.

The problem is that the profile specified with -d is not actually used, and the dependency information is loaded from the default profile when the script starts.