auto-correct: tweak phrasing

auto-correct: tweak phrasing

When help.autoCorrect is enabled, an invalid git command prints a
warning and a continuation message, which differs depending on
whether or not the value of help.autoCorrect is positive or
negative.

With help.autoCorrect = 15:

   WARNING: You called a Git command named 'lgo', which does not exist.
   Continuing under the assumption that you meant 'log'
   in 1.5 seconds automatically...

With help.autoCorrect < 0:

   WARNING: You called a Git command named 'lgo', which does not exist.
   Continuing under the assumption that you meant 'log'

The continuation message's phrasing is awkward.  This commit cleans it up.
As a bonus, we now use full-sentence strings which make translation easier.

With help.autoCorrect = 15:

   WARNING: You called a Git command named 'lgo', which does not exist.
   Continuing in 1.5 seconds, assuming that you meant 'log'.

With help.autoCorrect < 0:

   WARNING: You called a Git command named 'lgo', which does not exist.
   Continuing under the assumption that you meant 'log'.

Signed-off-by: Marc Branchaud <marcnarc@xiplink.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>