Favicon.ico Bad Request

[ThePopularizer]

Hi,

I'm getting a 'bad request' notice on GTMetrix when I activate Comet Cache:

Avoid Bad Requests
The following requests are returning 404/410 responses. Either fix the broken links, or remove the references to the non-existent resources.

[My Domain]/favicon.ico/

I wasn't planning to have a favicon.ico file. Is it possible to made this request conditional on the presence of the file?