minor symfony#10629 Fix grammar mistake (ocrampete16)

This PR was submitted for the 3.4 branch but it was merged into the 2.8 branch instead (closes symfony#10629).

Discussion
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Fix grammar mistake

Just something I stumbled upon while reading through the docs.

Commits
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b3566c2 Fix grammar error

Author: javiereguiluz

http_cache/esi.rst

@@ -95,7 +95,7 @@ First, to use ESI, be sure to enable it in your application configuration:
 
 Now, suppose you have a page that is relatively static, except for a news
 ticker at the bottom of the content. With ESI, you can cache the news ticker
-independent of the rest of the page::
+independently of the rest of the page::
 
     // src/AppBundle/Controller/DefaultController.php
 
@@ -158,7 +158,7 @@ used ``render()``.
     specification that is supported out of the box by the Symfony reverse
     proxy.
 
-The embedded action can now specify its own caching rules, entirely independent
+The embedded action can now specify its own caching rules entirely independently
 of the master page::
 
     // src/AppBundle/Controller/NewsController.php