minor #8930 Update file_permissions.rst (axzx)

This PR was merged into the 4.0 branch.

Discussion
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Update file_permissions.rst

change web directory to public

Commits
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2eb9afe Update file_permissions.rst

Author: weaverryan

setup/file_permissions.rst

@@ -4,7 +4,7 @@ Setting up or Fixing File Permissions
 In Symfony 3.x, you needed to do some extra work to make sure that your cache directory
 was writable. But that is no longer true! In Symfony 4, everything works automatically:
 
-* In the ``dev`` environment, ``umask()`` is used in ``bin/console`` and ``web/index.php``
+* In the ``dev`` environment, ``umask()`` is used in ``bin/console`` and ``public/index.php``
   so that any created files are writable by everyone.
 
 * In the ``prod`` environment (i.e. when ``APP_ENV`` is ``prod`` and ``APP_DEBUG``