gdbm: upgrade 1.23 -> 1.24

gdbm: upgrade 1.23 -> 1.24

ptest.patch
refreshed for 1.24.

Changelog:
===========
* New gdbm_load option: --update
* Fix semantics of gdbm_load -r
* Use getline in gdbmtool shell.
* New function: gdbm_load_from_file_ext
* Fix binary dump format for key and/or data of zero size.
* Fix location tracking and recover command in gdbtool.
* Fix possible buffer underflow in gdbmload.
* Ensure any padding bytes in avail_elem structure are filled with 0.
* Improve the documentation.

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>