Change customprefix setting name in caching_configuration.rst

Signed-off-by: Martin <31348196+Earl0fPudding@users.noreply.github.com>

Author: Earl0fPudding

admin_manual/configuration_server/caching_configuration.rst

@@ -187,7 +187,7 @@ The following options are available to configure when using a single redis serve
    'memcache.locking' => '\OC\Memcache\Redis',
    'memcache.distributed' => '\OC\Memcache\Redis',
    'memcache.local' =>'\OC\Memcache\Redis' ,
-   'memcache.customprefix' => 'mynextcloudprefix',
+   'memcache_customprefix' => 'mynextcloudprefix',
    'redis' => [
       // 'host'      => see connection parameters below
       // 'port'      => see connection parameters below
@@ -203,7 +203,7 @@ The following options are available to configure when using a redis cluster (all
    'memcache.locking' => '\OC\Memcache\Redis',
    'memcache.distributed' => '\OC\Memcache\Redis',
    'memcache.local' =>'\OC\Memcache\Redis' ,
-   'memcache.customprefix' => 'mynextcloudprefix',
+   'memcache_customprefix' => 'mynextcloudprefix',
    'redis.cluster' => [
       'seeds' => [ // provide some/all of the cluster servers to bootstrap discovery, port required
          'cache-cluster:7000',
@@ -385,7 +385,7 @@ collisions when using the same cache for multiple Nextcloud instances.
 If you want to make sure to prevent collisions alltogether, you can use the following
 setting to define your custom prefix::
 
-  'memcache.customprefix' => 'mynextcloudprefix',
+  'memcache_customprefix' => 'mynextcloudprefix',
 
 This also allows you to create ACLs in Redis and limit the keys specific users can access
 (e.g. if you want to isolate specific Nextcloud instances when using the same cache).