QDBusAbstractAdaptor: Cannot relay signal MyServer::newConnection(QDBusConnection): Unregistered input type in parameter list: QDBusConnection

Seen locally and e.g. in http://testresults.qt.io/logs/qt/qtbase/dd4f32259ce64456e63f4cc0303713d946ad14ea/LinuxopenSUSE_42_1x86_64LinuxopenSUSE_42_1x86_64GCCqtci-linux-openSUSE-42.1-x86_64DeveloperBuild_NoPch/85d6b000f945a84bc84a4f01f53ac65bc05cbe86/testrun_1471420038/testlog.txt.gz

Can't just add Q_DECLARE_METATYPE(QDBusConnection), since Connection is lacking a default ctor, and it's not clear whether there should be one.