Fix validator

Signed-off-by: Émile Ré <nemile.re@gmail.com>

pkg/validator/validator_email.go

@@ -35,7 +35,7 @@ func NotBlacklisted() ValidatorFunc {
 	return func(value any) *ValidationError {
 		err := notOneOfSlice(value)
 
-		if err == nil {
+		if err != nil {
 			return newValidationError(
 				ErrorCodeInvalidEmail,
 				"must not be blacklisted",