FIX: Videos and audio files were not associated to the post.

app/models/upload.rb

@@ -230,6 +230,12 @@ class Upload < ActiveRecord::Base
     url = url.sub(Discourse.asset_host, "") if Discourse.asset_host.present?
     # when using s3, we need to replace with the absolute base url
     url = url.sub(SiteSetting.s3_cdn_url, Discourse.store.absolute_base_url) if SiteSetting.s3_cdn_url.present?
+
+    # always try to get the path
+    if (uri = URI(url)).scheme
+      url = uri.path
+    end
+
     Upload.find_by(url: url)
   end