bug #19358 [Validator] Update the default message of the Charset constraint (xabbuh)

This PR was merged into the 7.1 branch.

Discussion
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[Validator] Update the default message of the `Charset` constraint

Commits
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cf4d724 update the default message of the Charset constraint

Author: OskarStark

reference/constraints/Charset.rst

@@ -96,7 +96,7 @@ encodings. This option accepts any value that can be passed to
 ``message``
 ~~~~~~~~~~~
 
-**type**: ``string`` **default**: ``The detected encoding "{{ detected }}" does not match one of the accepted encoding: "{{ encodings }}".``
+**type**: ``string`` **default**: ``The detected character encoding is invalid ({{ detected }}). Allowed encodings are {{ encodings }}.``
 
 This is the message that will be shown if the value does not match any of the
 accepted encodings.