Allow transition of the contract uploader token from 'rpc' to 'app' by changing function NodeAttachmentService.verifyVersionUniquenessForSignedAttachments so that a jar is no longer considered a duplicate of itself
to support this upgrade scenario:
A: new cordapp contract version is distributed via flow --> uploader token = 'p2p'
B: node admin makes it trusted by uploading it to the vault as described in  --> uploader token = 'rpc'
C: node admin decides to start it from the cordapps folder --> uploader token = 'app'
currently C fails with DuplicateContractClassException because the contract attachment is considered a duplicate of the attachment loaded in B - but it's not a duplicate, it is the SAME thing.