libedit: Update to version 20210910-3.1

libedit: Update to version 20210910-3.1

- v2 version is to extend from 20210714-3.1 to 20210910-3.1
- Update from 20210522-3.1 to 20210910-3.1
- Update rootfile
- Changelog
   2021-09-10 Jess Thrysoee
     * all: sync with upstream source
   2021-07-14 Jess Thrysoee
     * all: sync with upstream source
     * src/histedit.h: Add wcsdup declaration when ifndef HAVE_WCSDUP. Patch by Rainer Jung.
     * examples/wtc1.c: Fix warnings and add missing brace. Patch by Rainer Jung.

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>