Fix to the S2S - NMME/CFSv2 download and preprocessing step

[karsenau]

For the S2S based code, updated the NMME hindcast download (shell) script and the NMME preprocessing ("reorg") hindcast python script to account for the Jan- and Feb-2011 unique case for the NMME-based CFSv2 raw forecast data. This update will be required for future adaptions of the S2S code (e.g., sub region forecast domains).