comments: avoid using the gender of our users

comments: avoid using the gender of our users

We generally avoid specifying the gender of our users in order to be
more inclusive, but sometimes a few slip by due to habit.

Since by doing a little bit of rewording we can avoid this irrelevant
detail, let's do so.

Inspired-by: Derrick Stolee <dstolee@microsoft.com>
Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>