change history time to isoformat() to allow ISIS3's cathist understand it.
change history time to isoformat() to allow ISIS3's cathist understand it.

USGS-Astrogeology/GDAL_scripts,USGS-Astrogeology/GDAL_scripts,thareUSGS/GDAL_scripts,thareUSGS/GDAL_scripts,USGS-Astrogeology/GDAL_scripts,thareUSGS/GDAL_scripts,USGS-Astrogeology/GDAL_scripts,thareUSGS/GDAL_scripts