The log entry is:
Heartbeat: Tor's uptime is 23 days 0:00 hours, with 0 circuits open. I've sent 6.83 MB and received 177.12 MB.

I don’t think I made any changes to the torrc, intend to provide a relay.

I am using trickle to limit bandwidth consumption instead of the built-in method because I didn’t want to learn about the bursting concept.

ExecStart = /usr/bin/trickle -d 500 -u 500 -t .5 /usr/bin/tor --runasdaemon 0 --defaults-torrc /usr/share/tor/defaults-torrc -f /etc/tor/torrc --quiet

Running on Fedora.

Firewall allows external port 80 and 443 access to the server.