mms_load_data returns files outside of requested time range

[jameswilburlewis]

For example, in this call we're looking for FPI des-momsaux data for 2015-10-16. But files for many dates outside that range are returned:

pyspedas.projects.mms.mms_load_fpi(trange=['2015-10-16','2016-10-17'],data_rate='brst',datatype=['des-momsaux'])
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2015/10/24/mms1_fpi_brst_l2_des-momsaux_20151024152534_v3.4.0.cdf
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2016/09/26/mms1_fpi_brst_l2_des-momsaux_20160926134424_v3.4.0.cdf
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2016/09/26/mms1_fpi_brst_l2_des-momsaux_20160926134834_v3.4.0.cdf
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2016/09/26/mms1_fpi_brst_l2_des-momsaux_20160926135754_v3.4.0.cdf
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2016/09/26/mms1_fpi_brst_l2_des-momsaux_20160926140134_v3.4.0.cdf
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2016/09/26/mms1_fpi_brst_l2_des-momsaux_20160926140504_v3.4.0.cdf
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2016/09/26/mms1_fpi_brst_l2_des-momsaux_20160926141634_v3.4.0.cdf
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2016/09/26/mms1_fpi_brst_l2_des-momsaux_20160926141844_v3.4.0.cdf
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2016/09/26/mms1_fpi_brst_l2_des-momsaux_20160926142054_v3.4.0.cdf
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2016/09/26/mms1_fpi_brst_l2_des-momsaux_20160926144644_v3.4.0.cdf
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2016/09/26/mms1_fpi_brst_l2_des-momsaux_20160926150624_v3.4.0.cdf
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2016/09/26/mms1_fpi_brst_l2_des-momsaux_20160926151034_v3.4.0.cdf
08-Nov-24 11:55:54: Loading pydata/mms1/fpi/brst/l2/des-momsaux/2016/09/26/mms1_fpi_brst_l2_des-momsaux_20160926151804_v3.4.0.cdf

This doesn't happen in IDL -- there actually isn't any data in that time range, so nothing is returned.