matchbox-wm: Update to fix XChangeProperty datatype issue

matchbox-wm: Update to fix XChangeProperty datatype issue

This brings us to master HEAD and adds a single commit
compared to the previous version:
  8178e70 ewmh: Fix data type of a few XChangeProperty calls

This fixes broken Home-button in matchbox panel on mips64 (and
probably other platforms).

[YOCTO #9284]

(From OE-Core rev: b5ed789a6fe2d395b74a073c28060eb0f5a04a1b)

Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>