Fix Warnings (#566)

src/internal/NeoEsp8266UartMethod.cpp

@@ -139,7 +139,9 @@ void NeoEsp8266UartInterruptContext::Detach(uint8_t uartNum)
     ETS_UART_INTR_ENABLE();
 }
 
-void IRAM_ATTR NeoEsp8266UartInterruptContext::Isr(void* param)
+// The xtos_1int handler calls with param1 as the arg, param2 as a pointer
+// to an exception frame in memory.
+void IRAM_ATTR NeoEsp8266UartInterruptContext::Isr(void* param, [[maybe_unused]] void* exceptionFrame)
 {
     // make sure this is for us
     if (param == s_uartInteruptContext)