Config file uses `-` not `_` for word separation, unlike the cli where I got this from in the first place

Signed-off-by: Edward Evans <edward.evans@consensys.net>

templates/config.toml.j2

@@ -61,7 +61,7 @@ p2p-host="{{besu_host_ip}}"
 {% endif %}
 p2p-port={{besu_p2p_port}}
 {% if besu_max_peers is defined %}
-max_peers={{besu_max_peers}}
+max-peers={{besu_max_peers}}
 {% endif %}
 
 # metrics