fixes #359

Not sure why the logic of this function changed in https://github.com/creationix/nvm/commit/13781f242b0f8ae7d55274016884100550f9d6dd.

This puts back listing the uninstalled ls-remote versions.

There was only one use of PADDED_VERSION so it didn't need to be a variable. VERSION was not declared locally in the for loop, so I just added that too.