[port devel/dbus] Please remove the line deleting machine-id when port is uninstalled

[Yuri]

Line:
@unexec rm -f /var/db/dbus/machine-id
in pkg-plist causes machine-id to be regenerated every time port is 
upgraded.

Machine-id changes, and this makes it necessary to reboot the system or 
random things will be breaking. If machine-id is kept unchanged, there 
is the high likelihood that everything will still keep working.

Yuri