Catching incorrect credentials in getNASA

[rdjmacklin]

Hello,

Thanks for all the fixes recently! Just wanted to highlight another issue I've found in testing.

If I make a successful call to getNASA with correct credentials:

luna::getNASA(
product = "MCD12Q1",
start = "2010-01-01",
end = "2015-12-31",
aoi = study_area,
download = TRUE,
overwrite = FALSE,
username = "my correct EarthData email",
password = "my correct EarthData password"
)

A following call to getNASA with incorrect credentials will still succeed and not throw the expected error added in response to #38:

luna::getNASA(
product = "MCD12Q1",
start = "2010-01-01",
end = "2015-12-31",
aoi = study_area,
download = TRUE,
overwrite = FALSE,
username = "my incorrect EarthData email",
password = "my correct EarthData password"
)

I am wondering whether the call to httr::config() here in .cmr_download_one is not being overridden (see override = FALSE by default in httr::set_config) in the second call.

Thanks for taking a look!
Rory