dos: Change the DoS heartbeat line format
Fix a bug introduced in 94b56eaa which overwrite the connection message line.
Furthermore, improve how we generate that line by using a smartlist and change the format so it is clearer of what is being rejected/detected and, if applicable, which option is disabled thus yielding no stats.
Closes #40308 (closed)
Signed-off-by: David Goulet dgoulet@torproject.org