fix-typo: consecutive-word duplications

fix-typo: consecutive-word duplications

Correct unintentional duplication(s) of words, such as "the the",
and "can can" etc.

The changes are only applied to cases where it's fixing what is clearly
wrong or prone to misunderstanding, as suggested by the reviewers.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Helped-by: Denton Liu <liu.denton@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: ryenus <ryenus@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>