fix indent

Author: MrYamous

reference/configuration/framework.rst

@@ -2878,8 +2878,8 @@ app
 
 The cache adapter used by the ``cache.app`` service. The FrameworkBundle
 ships with multiple adapters: ``cache.adapter.apcu``, ``cache.adapter.system``,
- ``cache.adapter.filesystem``, ``cache.adapter.psr6``, ``cache.adapter.redis``,
- ``cache.adapter.memcached`` and ``cache.adapter.pdo``.
+``cache.adapter.filesystem``, ``cache.adapter.psr6``, ``cache.adapter.redis``,
+``cache.adapter.memcached`` and ``cache.adapter.pdo``.
 
 There's also a special adapter called ``cache.adapter.array`` which stores
 contents in memory using a PHP array and it's used to disable caching (mostly on