Let's accept the usual boolean parameters for LinkJournal. It's
confusing otherwise.
Previously we'd accept "no" but not the other values we typically accept
for "false". We'd not accept any values for "true".
With this change we'll accept all true and false values and will do
something somewhat reasonable: any false value is treated like "no"
previously was reated. And any true value is now treated like "auto".
We don't document the new values, since this logic is mostly redundant,
and it's probably better if people consider this an enum rather than a
bool.
Fixes: #16888
Lennart Poettering
58cf204730