Fix change brightness when sleeping

Prevents the panel to change screen brightness when sleeping.

Solves #975

nspanel_esphome.yaml

@@ -1176,8 +1176,19 @@ number:
     optimistic: true
     set_action:
       then:
-        - lambda: 'id(disp1).set_backlight_brightness(x/100);'
-        - lambda: 'id(disp1).send_command_printf("home.brightness.val=%i", int(x));'
+        - 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));'
         - globals.set:
             id: display_brightness_global
             value: !lambda 'return int(x);'