https not used for Twitter profile photo

I just tried your Comments + plugin and it went pretty well, but Firefox started to show an exclamation mark against my padlock, so I checked the page and found that the profile photo that is embedded from Twitter is not using https.

http://pbs.twimg.com/profile_images/470000847791747072/Y5GO6ILG_normal.jpeg

The image still loads if you add the s to http, so it would be great if you could ensure that these images are displayed using https when the site (my wordpress installation) is using https.

I've got to disable the plugin for now, to get my clean padlock back, but I hope you can modify the code to include this at some point.