This is cosmetic only, since openssl is the first one being defined, but
it avoids a warning in scripts/config, after upgrading to kconfig-v5.6:
tmp/.config-package.in:102839:warning: choice default symbol
'DNSDIST_OPENSSSL' is not contained in the choice
Signed-off-by: Eneas U de Queiroz <cotequeiroz@gmail.com>