[fix] follow up of PR-1856

- `` url: false`` breaks with existing installations
  e92755d358 (r89577339)

- PR-1856: https://github.com/searxng/searxng/pull/1856

- Comments from review: https://github.com/searxng/searxng/pull/1856#pullrequestreview-1176402810

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/settings.yml

@@ -76,9 +76,9 @@ server:
     X-Robots-Tag: noindex, nofollow
     Referrer-Policy: no-referrer
 
-redis:
-  # https://redis-py.readthedocs.io/en/stable/connections.html#redis.client.Redis.from_url
-  url: false
+# redis:
+#   # https://redis-py.readthedocs.io/en/stable/connections.html#redis.client.Redis.from_url
+#   url: unix:///usr/local/searxng-redis/run/redis.sock?db=0
 
 ui:
   # Custom static path - leave it blank if you didn't change