Check session lifetime adjusted.

When you provide SESSION_EXPIRE_AT_BROWSER_CLOSE
ssoauth is fine with it and does not cry about
values in SESSION_COOKIE_AGE

ssoauth/checks.py

@@ -113,6 +113,8 @@ def auth_urls_configured(app_configs, **kwargs):
 @register(Tags.security)
 def session_lifetime(app_configs, **kwargs):
     errors = list()
+    if conf.settings.SESSION_EXPIRE_AT_BROWSER_CLOSE:
+        return errors
     max_wanted = 60 * 60  # seconds
     if conf.settings.SESSION_COOKIE_AGE > max_wanted:
         errors.append(Error(