Fixed a RST syntax issue

Author: javiereguiluz

components/cache/adapters/array_cache_adapter.rst

@@ -8,7 +8,7 @@ Array Cache Adapter
 Generally, this adapter is useful for testing purposes, as its contents are stored in memory
 and not persisted outside the running PHP process in any way. It can also be useful while
 warming up caches, due to the :method:`Symfony\\Component\\Cache\\Adapter\\ArrayAdapter::getValues`
-method:
+method::
 
     use Symfony\Component\Cache\Adapter\ArrayAdapter;