src/lib/dhcpsrv/host_data_source_factory.cc
    HostDataSourceFactory::create(const std::string& dbaccess)
        - Removed logging from exception throwing conditions
        - Minor clean up of the method itself

src/lib/dhcpsrv/dhcpsrv_messages.mes
    Removed obsoleted error messages:
        DHCPSRV_HOSTDB_NOTYPE
        DHCPSRV_UNKNOWN_HOST_DB