Create Site Titled "Blog"

Hi! I just recently installed WordPress and enabled Mutlisite subdirectories.
My website is found here.

I want to add a site titled “Blog” so that I can run a custom theme under the permalink yagershots/blog. Unfortunately, when I go to “Add New” while logged in as Network Admin, it says “The following words are reserved for use by WordPress functions and cannot be used as blog names: page, comments, blog, files, feed”

Is there any option to change this?

Thank you!