uninstall.sh: prevent deleting none related homebrew folder

I uninstalled homebrew because of an problem.
Uninstaller prompted my to delete: /usr/local/MacGPG2/ which isn't a Homebrew related file so skip it to be shown on none deleted dirs and files by the script.

uninstall.sh

@@ -462,6 +462,8 @@ fi
 dir_children "${HOMEBREW_REPOSITORY}" "${HOMEBREW_PREFIX}" |
   sort -u >"${tmpdir}/residual_files"
 
+grep -v "MacGPG2" "${tmpdir}/residual_files" >"${tmpdir}/filtered_residual_files"
+
 if [[ -s "${tmpdir}/residual_files" && -z "${opt_quiet}" ]]
 then
   echo "The following possible Homebrew files were not deleted:"