minor #5523 Custom voter example, fix missing curly brace (snroki)

This PR was submitted for the 2.7 branch but it was merged into the 2.6 branch instead (closes #5523).

Discussion
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Custom voter example, fix missing curly brace

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.6 / 2.7 / 3.0
| Fixed tickets |

Commits
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8a0297f Custom voter example, fix missing curly brace

cookbook/security/voters_data_permission.rst

@@ -111,7 +111,8 @@ edit a particular object. Here's an example implementation:
                     }
 
                     break;
-
+            }
+            
             return false;
         }
     }