minor #4962 cookbok/security/acl.rst (DaliusK)

This PR was merged into the 2.3 branch.

Discussion
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cookbok/security/acl.rst

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.3+
| Fixed tickets | ?

I believe ACE stands only for Access Control Entry, as used e.g. at http://symfony.com/doc/current/cookbook/security/acl_advanced.html

Commits
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243519f Update acl.rst

cookbook/security/acl.rst

@@ -91,7 +91,7 @@ Coming back to the small example from the beginning, you can now implement
 ACL for it.
 
 Once the ACL is created, you can grant access to objects by creating an
-Access Control Entity (ACE) to solidify the relationship between the entity
+Access Control Entry (ACE) to solidify the relationship between the entity
 and your user.
 
 Creating an ACL and Adding an ACE