sequencer: do not translate reflog messages

sequencer: do not translate reflog messages

Traditionally, reflog messages were never translated, in particular not
on storage.

Due to the switch of more parts of git to the sequencer, old changes in
the sequencer code may lead to recent changes in git's behaviour. E.g.:
c28cbc5ea6 ("sequencer: mark action_name() for translation", 2016-10-21)
marked several uses of `action_name()` for translation. Recently, this
lead to a partially translated reflog:

`rebase: fast-forward` is translated (e.g. in de to `Rebase: Vorspulen`)
whereas other reflog entries such as `rebase (pick):` remain
untranslated as they should be.

Change the relevant line in the sequencer so that this reflog entry
remains untranslated, as well.

Signed-off-by: Michael J Gruber <git@grubix.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>