xrdp is not pre-configured to use correct Xorg

When xrdp is used in xorgxrdp mode, it starts Xorg after user authentication. Correct path to non-suid Xorg should be configured in /etc/xrdp/sesman.ini in [Xorg] section. Currently the line is param=Xorg which points to Xorg wrapper and prevents Xorg from being started. Correct line for Alpine is param=/usr/libexec/Xorg.

I would expect that together with #12896 (closed) this should make xrdp usable out of the box.