Default return when signatures shouldn't be checked

See

SignatureCheckDialogs::CheckSignaturesInYaST()

Callback handler function. Required callback prototype is boolean(string filename, string requested_digest, string found_digest). The callback function should ask user whether the wrong digest can be accepted, returned true value means to accept the file.

Callback handler function. Required callback prototype is boolean(string filename, string name). The callback function should ask user whether the uknown digest can be accepted, returned true value means to accept the digest.