extdiff: prevent exception on double-translation
The docstring is translated twice: once when used as a format string,
and once on display. The second translation fails when the first
translation introduces non-ASCII characters in the string.
The problem is that the gettext module calls unicode(message) on the
string, i.e., it decodes it to a Unicode string using the ASCII
encoding (the default encoding). By translating it into a Unicode
string here, the unicode() call becomes a noop.
% issue1810: inotify and fetch
adding foo
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
adding bar
adding spam
% issue1719: inotify and mq
% inserve
popping test.patch
patch queue now empty
% st should not output anything
applying test.patch
now at: test.patch
% st should not output anything