Remove duplicate UTF-8 check

All strings are already validated in packet__read_string().

src/handle_publish.c

@@ -177,11 +177,6 @@ int handle__publish(struct mosquitto_db *db, struct mosquitto *context)
 			}
 		}
 	}
-	if(mosquitto_validate_utf8(topic, slen) != MOSQ_ERR_SUCCESS){
-		log__printf(NULL, MOSQ_LOG_INFO, "Client %s sent topic with invalid UTF-8, disconnecting.", context->id);
-		mosquitto__free(topic);
-		return 1;
-	}
 
 #ifdef WITH_BRIDGE
 	rc = bridge__remap_topic_in(context, &topic);