[Taranis] Cleaner reboot on USB disconnect, longer LCD initialization delay to compensate for the time saved removing USB initialisation

src/targets/taranis/usbd_usr.cpp

@@ -119,6 +119,12 @@ void USBD_USR_DeviceConnected (void)
 */
 void USBD_USR_DeviceDisconnected (void)
 {
+  // TODO: Separate the shutdown operations in main() into a shutdown() function in opentx.cpp,
+  // and call that before the NVIC_SystemReset()?
+  g_eeGeneral.unexpectedShutdown = 0;
+  eeDirty(EE_GENERAL);
+  eeCheck(true);
+  
   NVIC_SystemReset();
 }