Remove connection attempts field from Config

include/config.h

@@ -12,8 +12,7 @@ typedef struct {
     const char *topic;
     const char *device_id;
     int mqtt_port;
-    long sleep_time;
-    int connection_attempts;
+    unsigned long sleep_time;
 } Config;
 
 void initialize_config(Config *config, JsonDocument json);