improve strict option value deprecation

UPGRADE-3.4.md

@@ -0,0 +1,8 @@
+UPGRADE FROM 3.3 to 3.4
+=======================
+
+Validator
+---------
+
+ * not setting the `strict` option of the `Choice` constraint to `true` is
+   deprecated and will throw an exception in Symfony 4.0

UPGRADE-4.0.md

@@ -507,6 +507,9 @@ TwigBridge
 Validator
 ---------
 
+ * The default value of the `strict` option of the `Choice` constraint was changed
+   to `true`. Using any other value will throw an exception.
+
  * The `DateTimeValidator::PATTERN` constant was removed.
 
  * `Tests\Constraints\AbstractConstraintValidatorTest` has been removed in

src/Symfony/Component/Validator/CHANGELOG.md

@@ -1,6 +1,12 @@
 CHANGELOG
 =========
 
+3.4.0
+-----
+
+ * not setting the `strict` option of the `Choice` constraint to `true` is
+   deprecated and will throw an exception in Symfony 4.0
+
 3.3.0
 -----
 

src/Symfony/Component/Validator/Constraints/ChoiceValidator.php

@@ -58,8 +58,8 @@ class ChoiceValidator extends ConstraintValidator
             $choices = $constraint->choices;
         }
 
-        if (false === $constraint->strict) {
+        if (true !== $constraint->strict) {
-            @trigger_error('Setting the strict option of the Choice constraint to false is deprecated since version 3.2 and will be removed in 4.0.', E_USER_DEPRECATED);
+            @trigger_error('Not setting the strict option of the Choice constraint to true is deprecated since version 3.4 and will throw an exception in 4.0.', E_USER_DEPRECATED);
         }
 
         if ($constraint->multiple) {