RSA Verify will return true in default

[zcqzcg]

hyperledger-fabric-bccsp-rsa/bccsp/src/doublechain/fabric/bccsp/rsa/plugin.go

Line 233 in ce4c37e

return true, nil

Please see that switch function, if the two cases misses, then it will return true in default.

I am not sure if it's a bug or so.

Just a notice for you, if I am wrong please close this issue for good.

Thanks!