wishlist: git gui not listing untracked files in unstaged list

Many projects are organized so that the result of compilation is mixed with
sources.
It would be very useful to configure git gui so that untracked files are not
listed in the un-staged list.
I have patched git gui, function rescan_stage2, line 1414 to do so:
  # set fd_lo [eval git_read ls-files --others -z $ls_others]
  set fd_lo [eval git_read ls-files -z $ls_others]

but it would be nice to make this behavior tunable via the "Options..." menu.