Fix bug introduced in recent small refactoring, left a reference to a deleted variable

Author: jaltekruse

ricecooker/utils/downloader.py

@@ -390,6 +390,7 @@ def download_assets(
                 if not ext:
                     ext = ".html"
 
+                subpath = filename
                 # Add the existing filename in front of index.xxx, this can contain slashes and those will result
                 # in subdirectories created in the downloaded version. This ensures multiple instances of extensionless
                 # resources referenced from a page won't clobber each other.