Better description for ignore_system_dns

DNSCrypt/dnscrypt-proxy@b9f8f78

Author: d3cim

config/dnscrypt-proxy.toml

@@ -258,7 +258,17 @@ dnscrypt_ephemeral_keys = true
 bootstrap_resolvers = ['45.11.45.11:53']
 
 
-## Always use the bootstrap resolver before the system DNS settings.
+## When internal DNS resolution is required, for example to retrieve
+## the resolvers list:
+##
+## - queries will be sent to dnscrypt-proxy itself, if it is already
+##   running with active servers (*)
+## - or else, queries will be sent to fallback servers
+## - finally, if `ignore_system_dns` is `false`, queries will be sent
+##   to the system DNS
+##
+## (*) this is incompatible with systemd sockets.
+## `listen_addrs` must not be empty.
 
 ignore_system_dns = true