docs: Update emqx_conf_schema.hocon

rel/i18n/emqx_conf_schema.hocon

@@ -74,7 +74,7 @@ cluster_quic_lb_mode.desc:
 - 1: server_ip
 - 2: server_id_fixed
 - N: when N>2 server_id_fixed and server_id is N
-- IfName: when IfName is string, server_id will be set to the first ip on interface IfName, ipv4 only"""
+- IfName: when IfName is string, server_id will be set to the first ip on interface IfName, ipv4 only."""
 
 cluster_quic_lb_mode.label:
 """ QUIC stack LB Mode """