less: Update to version 668

less: Update to version 668

- Update from version 661 to 668
- Update of rootfile not required
- Changelog
    668
	* Make 256/true colors work better on Windows without -Da
	  (github #539, github #546, github #562).
	* Fix build using --with-secure (github #544).
	* Fix crash when using --header on command line (github #545).
	* Fix possible crash when scrolling left/right or toggling -S (github #547).
	* Fix bug when using #stop in a lesskey file (github #551).
	* Fix bug when using --shift or --match-shift on command line with
	  a parameter starting with '.' (github #554).
	* Fix bug in R command when file size changes (github #553).
	* Fix bug using --header when file does not fill screen (github #556).
	* Fix ^X bug when output is not a terminal (github #558).
	* Fix bug where ^Z is not handled immediately (github #563).
	* Fix bug where first byte from a LESSOPEN filter is deleted if it is
	  greater than 0x7F (github #568).
	* Fix uninitialized variable in edit_ifile (github #573).
	* Fix incorrect handling of UTF-8 chars in prompts (github #576).

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