fix outdated grub-legacy bootloader name references

functions/defaults.sh

@@ -616,7 +616,7 @@ Check_config_defaults ()
 	case "${LIVE_IMAGE_TYPE}" in
 		hdd*)
 			case "${LB_FIRST_BOOTLOADER}" in
-				grub)
+				grub-legacy)
 					Echo_error "You have selected a combination of bootloader and image type that is currently not supported by live-build. Please use either another bootloader or a different image type."
 					exit 1
 					;;

scripts/build/binary_hdd

@@ -55,7 +55,7 @@ Check_package host /sbin/losetup mount
 
 for BOOTLOADER in $(echo "${LB_BOOTLOADERS}" | tr "," "\n"); do
 	case "${BOOTLOADER}" in
-		grub)
+		grub-legacy)
 			Check_package chroot /usr/sbin/grub grub
 			;;
 	esac

scripts/build/binary_iso

@@ -120,7 +120,7 @@ do
 		XORRISO_OPTIONS="${XORRISO_OPTIONS} -eltorito-alt-boot "
 	fi
 	case "${BOOTLOADER}" in
-		grub)
+		grub-legacy)
 			XORRISO_OPTIONS="${XORRISO_OPTIONS} -no-emul-boot -boot-load-size 4 -boot-info-table"
 			XORRISO_OPTIONS="${XORRISO_OPTIONS} -b boot/grub/stage2_eltorito"
 			XORRISO_EXCLUDE="boot/grub/stage2_eltorito"