Update lis_default_configuration.json with saga-gis default values

doc/lis_default_configuration.json

@@ -45,7 +45,9 @@
     "shaded_snow": {
         "detect_shaded_snow": true,
         "hillshade_lim": 0.2,
-        "shaded_snow_pass": 160
+        "shaded_snow_pass": 160,
+        "sagagis_tools_libs": "",
+        "sagagis_thresh": 200
     },
     "water_mask":{
          "water_mask_raster_values":[1]