feat (HWCDC) : port 2.0.15

Changed header for a few functions.

Author: SuGlider

cores/esp32/HWCDC.h

@@ -70,10 +70,7 @@ class HWCDC : public Stream {
   size_t write(const uint8_t *buffer, size_t size);
   void flush(void);
 
-  inline static bool isPlugged(void) {
-    return usb_serial_jtag_is_connected();
-  }
-
+  static bool isPlugged(void);
   inline static bool isConnected(void) {
     return isCDC_Connected();
   }