Feed the watchdog within the busy-wait loop in order to prevent prema…

…ture resets by the watchdog. (#77)

This change needs at least ArduinoIoTCloud:v1.0.0.

src/NB.cpp

@@ -23,6 +23,14 @@
 
 #include "NB.h"
 
+__attribute__((weak)) void mkr_nb_feed_watchdog()
+{
+    /* This function can be overwritten by a "strong" implementation
+     * in a higher level application, such as the ArduinoIoTCloud
+     * firmware stack.
+     */
+}
+
 enum {
   READY_STATE_SET_ERROR_DISABLED,
   READY_STATE_WAIT_SET_ERROR_DISABLED,
@@ -96,6 +104,8 @@ NB_NetworkStatus_t NB::begin(const char* pin, const char* apn, const char* usern
           break;
         }
 
+        mkr_nb_feed_watchdog();
+
         delay(100);
       }
     } else {