Incorrect SDE on simpleType with lengthKind 'implicit' even if type is used with a computed element

In my types xsd file I have default lengthKind 'implicit' and this type definition:

```
<simpleType name="messageVersion">
  <xs:restriction base="xs:string">
    <xs:maxLength value="13"/>
  </xs:restriction>
</simpleType>
```
In a different place I have this:
```
<element name="value" type="ms2045:messageVersion"
   dfdl:inputValueCalc="

{      if (fn:exists(../vmf_hdr_C)) then ../vmf_hdr_C else ../vmf_hdr_D1    }

"/>
```
This uses the simpleType definition, but notice this is a computed element (inputValueCalc).
 
Hence, all format properties should be ignored, and we should not get an SDE indicating that the value element needs to have both minLength and maxLength and for them to be equal.