nano: Update to 2.5.1

nano: Update to 2.5.1

Excerpt form 'NEWS':
"It includes fixes for a syntax-highlighting bug and a positionlog bug,
it disables a time-eating multiline regex in the C syntax,
and it adds an escape hatch to the WriteOut menu when
--tempfile is used: the discardbuffer command, ^Q.  It
also has translation updates for fifteen languages, and
a small fix in the softwrap code."

Signed-off-by: Matthias Fischer <matthias.fischer@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>