feat: Use default logo when custom is not found (#1055)

    if [ ! -s "$DEST.rom" ]; then

      [ ! -s "$OVMF/$ROM" ] && error "UEFI boot file ($OVMF/$ROM) not found!" && exit 44

      logo="/var/www/img/${PROCESS,,}.ffs"

      [ ! -s "$logo" ] && logo="/var/www/img/qemu.ffs"

      [ ! -s "$logo" ] && LOGO="N"

      if [[ "${LOGO:-}" == [Nn]* ]]; then

        cp "$OVMF/$ROM" "$DEST.tmp"

      else

        if ! /run/utk.bin "$OVMF/$ROM" replace_ffs LogoDXE "/var/www/img/${PROCESS,,}.ffs" save "$DEST.tmp"; then

        if ! /run/utk.bin "$OVMF/$ROM" replace_ffs LogoDXE "$logo" save "$DEST.tmp"; then

          warn "failed to add custom logo to BIOS!"

          cp "$OVMF/$ROM" "$DEST.tmp"

        fi