Amend commit message for "BB 43322: Customize the font visibility lists"

I noticed when checking the 140-146 diff that we used to rename files as part of 3f55f2b6:

gfx/thebes/StandardFonts-linux.inc to gfx/thebes/StandardFonts-linux-upstream.inc
gfx/thebes/StandardFonts-macos.inc to gfx/thebes/StandardFonts-macos-upstream.inc

However, in the 144 branch this was no longer the case: see eb63f577 and d8e32c3a. According to the latter, this was to restore a build error.

I imagine this was handled fine, and something else was used besides renames to exclude the files.

However, the commit message still says:

Also, rename the files with the upstream lists, to make sure we do not use them by mistake.

which is no longer the case. We should probably update this part of the commit message or remove it.