Remove geoknife download config workaround in GCM munge pipeline

[lindsayplatt]

We had an issue with some of the downloads failing and noted it here in this geoknife issue. In the meantime, we needed to keep moving on the downloads, so implemented a workaround (see it here). Dave Blodgett resolved the issue here. We should switch to the development version of geoknife (unless there has been a release of geoknife following that fix) and remove the the temporary workaround (don't forget to make sure the wait = TRUE or wait() command is added back!).

Note that we should probably do this along with #279, so that we only need to redownload once (since this changes the download fxn and would cause everything to rebuild).