Fix two typos introduced by the following commits:

+ 31fba9d3 (diff-parseopt: convert --[src|dst]-prefix, 2019-03-24)
+ ed8b4132 (remote-curl: mark all error messages for translation,
  2019-03-05)
Signed-off-by: NJiang Xin <worldhello.net@gmail.com>
Acked-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>