xz: Update to version 5.6.1

xz: Update to version 5.6.1

- Update from version 5.6.0 to 5.6.1
- Update of rootfile
- Changelog
    5.6.1
	    * liblzma: Fixed two bugs relating to GNU indirect function (IFUNC)
	      with GCC. The more serious bug caused a program linked with
	      liblzma to crash on start up if the flag -fprofile-generate was
	      used to build liblzma. The second bug caused liblzma to falsely
	      report an invalid write to Valgrind when loading liblzma.
	    * xz: Changed the messages for thread reduction due to memory
	      constraints to only appear under the highest verbosity level.
	    * Build:
	        - Fixed a build issue when the header file <linux/landlock.h>
	          was present on the system but the Landlock system calls were
	          not defined in <sys/syscall.h>.
	        - The CMake build now warns and disables NLS if both gettext
	          tools and pre-created .gmo files are missing. Previously,
	          this caused the CMake build to fail.
	    * Minor improvements to man pages.
	    * Minor improvements to tests.

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>