message: Fix non-virtual dtor error in FailoverCallback
diff: @@ -22,7 +22,7 @@ namespace iroha {
  * Note: the class is a workaround for SOCI 4.0, support in future versions
  * is not guaranteed
  */
  - class FailoverCallback : public soci::failover_callback {
  + class FailoverCallback final : public soci::failover_callback {
  public:
  using InitFunctionType = std::function<void(soci::session &)>;
  FailoverCallback(
  