show wifi disconnect reason as text

src/web/WebStatusService.h

@@ -33,6 +33,8 @@ class WebStatusService {
     void webStatusService(AsyncWebServerRequest * request);
     void WiFiEvent(WiFiEvent_t event, WiFiEventInfo_t info);
     void mDNS_start() const;
+    const char * disconnectReason(uint8_t code);
+
 };
 
 } // namespace emsesp