Undo ERA_NATIVE levels change in geos2wrf.F

The change from 137 to 89 levels or ERA_NATIVE to reflect the number of thinned levels used for LASSO corrupts the output from geos2wrf. Therefore, this change is being undone and reset to the full level count of the ERA data. A better way to handle thinning of the GEOS aerosol intermediate files is to first generate them for all levels followed by thinning them using WPS's mod_lev program.