Loading Cluster FGM data from SPDF fails for dates in 2003

[jameswilburlewis]

This call:

data = pyspedas.cluster.fgm(probe=[1, 2, 3, 4], trange=['2003-08-17/16:40', '2003-08-17/16:45'], time_clip=True)

fails with a series of errors:

10-Jan-24 18:41:20: Downloading remote index: https://spdf.gsfc.nasa.gov/pub/data/cluster/c1/up/fgm/2003/
10-Jan-24 18:41:21: Remote index not found: https://spdf.gsfc.nasa.gov/pub/data/cluster/c1/up/fgm/2003/

This URL format only seems to hold for data from 2009 and later.

There is a different set of URLs that apparently are good for the whole mission, for example:

https://spdf.gsfc.nasa.gov/pub/data/cluster/c1/fgm/mfield_3dvect_fullreso/2003/c1_cp_fgm_full_20030101_v20140306.cdf

But it's a little weird that they have dates rather than version numbers in the filenames....maybe our wildcard downloads are robust enough to deal with it?