bug#66327: PARTED_CHECK_LIBPARTED shipped with parted 3.6 fails to detect it

autoconf macro PARTED_CHECK_LIBPARTED requires ped_get_version() to
return 3 part version string or otherwise it fails with "3.6, bad
version string"

	if ( !(version = ped_get_version ()) )
		exit(EXIT_FAILURE);
	if (sscanf(version, "%d.%d.%d", &major, &minor, &micro) != 3) {
		printf("%s, bad version string\n", version);
		exit(EXIT_FAILURE);
	}

Therefore it fails for two part version string like "3.6".