fix(query): cast $not objects

Fix #4495

lib/cast.js

@@ -17,6 +17,7 @@ var ALLOWED_GEOWITHIN_GEOJSON_TYPES = ['Polygon', 'MultiPolygon'];
 module.exports = function cast(schema, obj) {
   var paths = Object.keys(obj),
       i = paths.length,
+      _keys,
       any$conditionals,
       schematype,
       nested,
@@ -203,6 +204,17 @@ module.exports = function cast(schema, obj) {
             }
 
             if ($cond === '$not') {
+              if (nested && schematype && !schematype.caster) {
+                _keys = Object.keys(nested);
+                if (_keys.length && _keys[0].charAt(0) === '$') {
+                  for (var key in nested) {
+                    nested[key] = schematype.castForQuery(key, nested[key]);
+                  }
+                } else {
+                  val[$cond] = schematype.castForQuery($cond, nested);
+                }
+                continue;
+              }
               cast(schematype.caster ? schematype.caster.schema : schema, nested);
             } else {
               val[$cond] = schematype.castForQuery($cond, nested);