(Update camera_pins.h) Flash does not work on the esp32cam (espressif#8091)

it is planned to use the flash led but a normal led is configured instead

Author: tnagorran

Diff for: libraries/ESP32/examples/Camera/CameraWebServer/camera_pins.h

@@ -155,7 +155,8 @@
 #define HREF_GPIO_NUM     23
 #define PCLK_GPIO_NUM     22
 
-#define LED_GPIO_NUM      33
+// 4 for flash led or 33 for normal led
+#define LED_GPIO_NUM       4
 
 #elif defined(CAMERA_MODEL_TTGO_T_JOURNAL)
 #define PWDN_GPIO_NUM      0