Server did not start after upgrade to postgresql 10

[Simon Pepping <spepping@leverkruid.eu>]

When I upgraded from postgresql 9.6 to 10, the postgres server failed to
start. Error message: 'max_wal_senders must be less than
max_connections'. The configuration file
/etc/postgresql/10/main/postgresql.conf has the line

#max_wal_senders = 0

suggesting that 0 is a default value. When I removed the comment symbol,
effectively including this setting, I could start the server. This is
different from 9.6.

Is this a known problem, or should I report it as a bug?

Simon