ReferencePillar should not deliver the value of an incorrect checksum when responding to a failed ReplaceFile

The ReferencePillar currently tells both the expected and the invalid checksum when responding to a ReplaceFile, which was failing due to non-matching checksums.

[Oct 10, 2012 3:46:59 PM] 5088761f: REPLACE_FILE for file SanityTestFile: COMPONENT_FAILED: ContributorID reference2 ResponseCode: reference2, Wrong checksum! Expected: [940a51b250e7aa82d8e8ea31217ff267], but calculated: [549e80f319af070f8ea8d0f149a149c2]