Display internal sensor value when wifi is out

Before it was showing on home page only when API was out. This adds a test for WiFi.

nspanel_esphome.yaml

@@ -923,11 +923,13 @@ sensor:
       - lambda: return x + id(temperature_correction_global);
     on_value:
       then:
-        # Show panel's temperature if API is out
+        # Show panel's temperature if API or Wi-Fi are out
         - if:
             condition:
               - not:
-                  api.connected:
+                  - and:
+                      - api.connected:
+                      - wifi.connected:
             then:
               - lambda: id(disp1).set_component_text_printf("home.current_temp", "%.1f°", id(temp_nspanel).state);