[SECURITY] Fedora 28 Update: botan2-2.7.0-1.fc28

Botan is a BSD-licensed crypto library written in C++. It provides a wide variety of basic cryptographic algorithms, X.509 certificates and CRLs, PKCS #10 certificate requests, a filter/pipe message processing system, and a wide variety of other features, all written in portable C++. The API reference, tutorial, and examples may help impart the flavor of the library. This is the current stable release branch 2.x of Botan.