gawk: Update to version 5.3.1

gawk: Update to version 5.3.1

- Update from version 5.3.0 to 5.3.1
- Update of rootfile
- Changelog
    5.3.1
	1. More subtle issues related to uninitialized array elements have
	   been fixed.
	2. A number of bugs in the debugger related to handling of arrays
	   have been fixed.
	3. Some subtle bugs in the API have been fixed.
	4. Use of MPFR is now possible again on 32-bit Power PC Mac systems.
	5. Race conditions around broken pipes for system() and read and write
	   pipes should now be closed off.
	6. Support for OSF/1 has been removed.
	7. The never-documented --nostalgia option has been removed. It was
	   causing bug reports.
	8. The implementation of printf/sprintf has been thoroughly reworked
	   in order to make the code more maintainable and to fix a goodly
	   number of corner cases.
	9. As usual, there have been several minor code cleanups and bug fixes.
	   See the ChangeLog for details.

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