[FreeNX-kNX] Misleading error message in nxloadconfig

[Jeffrey J. Kosowsky]

The warning  messages:
	Warning: Invalid value "COMMAND_SMBMOUNT=smbmount". You'll not be able
	to use SAMBA.
	Warning: Invalid value "COMMAND_SMBUMOUNT=smbumount". You'll not be
	able to use SAMBA.
are a bit misleading. The probably should say something more like
	"... You'll not be able to use SAMBA over port 139 (smbfs)"

Also, similar, parallel error messages should probably now be added
for COMMAND_SMBMOUNT_CIFS and COMMAND_SMBUMOUNT_CIFS.

More, generally, nxloadconfig could probably use a good scrubbing
since checking seems to be missing from the addition of several new shell variables.