fix for object link nullification

src/object-store/src/object_accessor.hpp

@@ -180,7 +180,12 @@ namespace realm {
 
         size_t column = property.table_column;
         if (property.is_nullable && Accessor::is_null(ctx, value)) {
+            if (property.type == PropertyTypeObject) {
+                m_row.nullify_link(column);
+            }
+            else {
                 m_row.set_null(column);
+            }
             return;
         }