Fix change brightness when sleeping

Prevents the panel to change screen brightness when sleeping.

Solves #975

nspanel_esphome.yaml

@@ -1175,6 +1175,17 @@ number:
     restore_value: true
     optimistic: true
     set_action:
+      then:
+        - if:
+            condition:
+              - binary_sensor.is_on: nextion_init
+            then:
+              - if:
+                  condition:
+                    - not:
+                      - text_sensor.state: # Is sleeping?
+                          id: current_page
+                          state: 'screensaver'
                   then:
                     - lambda: 'id(disp1).set_backlight_brightness(x/100);'
               - lambda: 'id(disp1).send_command_printf("home.brightness.val=%i", int(x));'