Your browser has cached the shortcut icon.
If you want to replace it, you'll need to provide a new icon. The easiest option is to use a tool to generate the files and markup you need - for example,
Favicon Generator[
^].
If you want to remove it, you'll need to clear your browser's cache. However, if other users have accessed your site whilst the icon was present, they will also need to clear their cache to get rid of the icon.