FIX: Old Upload#url scheme support for Upload.get_from_url.

This is for backwards compatibility purposes. Even if `Upload#url` has a
format that we don't recognize, we should still return the upload object
as long as the upload record is present.

spec/models/upload_spec.rb

@@ -122,6 +122,12 @@ describe Upload do
       end
     end
 
+    it "should return the right upload as long as the upload's URL matches" do
+      upload.update!(url: "/uploads/default/12345/971308e535305c51.png")
+
+      expect(Upload.get_from_url(upload.url)).to eq(upload)
+    end
+
     describe 'for a url a tree' do
       before do
         upload.update!(url: