Update cache_invalidation.rst

Author: andrerom

components/cache/cache_invalidation.rst

@@ -62,7 +62,7 @@ method.
 
     When using a Redis backend, consider using :ref:`RedisTagAwareAdapter <redis-tag-aware-adapter>`
     which is optimized for this purpose. When using File system, likewise consider to use
-    :ref:`FilesystemTagAwareAdapter <filesystem-tag-aware-adapter>`
+    :ref:`FilesystemTagAwareAdapter <filesystem-tag-aware-adapter>`.
 
 The :class:`Symfony\\Component\\Cache\\Adapter\\TagAwareAdapter` class implements
 instantaneous invalidation (time complexity is ``O(N)`` where ``N`` is the number