django: settings: Don't set USE_L10N on newer versions

- Eliminate a Django warning message.

- This setting has been deprecated. It will be remove in Django 5.0 and is
always on.

Tests:

- On Debian stable, django.VERSION <= (4,0) evaluates to True and on testing it
evaluates to False.

- After the patch, the warning related to USE_L10N has disappeared.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: Veiko Aasa <veiko17@disroot.org>

plinth/settings.py

@@ -26,6 +26,8 @@ See: https://docs.djangoproject.com/en/dev/ref/settings/
 
 """
 
+import django
+
 ALLOWED_HOSTS = ['*']
 
 _pwd = 'django.contrib.auth.password_validation'
@@ -200,7 +202,8 @@ TEMPLATES = [
 
 TIME_ZONE = 'UTC'
 
-USE_L10N = True
+if django.VERSION <= (4, 0):
+    USE_L10N = True
 
 USE_TZ = True