fix: mqtt recv cycle feed watchdog when cycle interval is 0

Send cycle and recv cycle share one mutex,
For increasing mqtt thoughtput, set receive cycle to 0,
mqtt recv cycle feed watchdog when cycle interval=0

Author: ustccw

components/mqtt/paho/MQTTClient-C/src/MQTTClient.c

@@ -18,6 +18,7 @@
 #include <stdio.h>
 #include <string.h>
 #include "esp_log.h"
+#include "esp_task_wdt.h"
 #include "MQTTClient.h"
 
 static const char *TAG = "mc";
@@ -438,6 +439,10 @@ void MQTTRun(void *parm)
     while (1) {
         TimerCountdownMS(&timer, CONFIG_MQTT_RECV_CYCLE); /* Don't wait too long if no traffic is incoming */
 
+#if CONFIG_MQTT_RECV_CYCLE == 0     /* The smaller cycle, the greater throughput */
+        esp_task_wdt_reset();
+#endif
+
 #if defined(MQTT_TASK)
         MutexLock(&c->mutex);
 #endif