minor #16009 [Validator] Add missing dot (sebpacz)

This PR was merged into the 4.4 branch.

Discussion
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[Validator] Add missing dot

The default NotBlank constraint message ends with a dot.

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Commits
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bd8f1e3 [Validator] Add missing dot

Author: javiereguiluz

validation.rst

@@ -179,7 +179,7 @@ message:
 .. code-block:: text
 
     Object(App\Entity\Author).name:
-        This value should not be blank
+        This value should not be blank.
 
 If you insert a value into the ``name`` property, the happy success message
 will appear.