* #7845: fixed more Weffc++ warnings

daemon/src/dbus/configurationmanager.cpp

daemon/src/dbus/configurationmanager.h

daemon/src/managerimpl.cpp

daemon/src/preferences.cpp

daemon/src/preferences.h

daemon/src/video/video_preview.cpp

daemon/src/video/video_preview.h

daemon/src/video/video_receive_thread.cpp

daemon/src/video/video_receive_thread.h

daemon/src/video/video_rtp_session.cpp

daemon/src/video/video_send_thread.cpp

daemon/src/video/video_send_thread.h

daemon/src/video/video_v4l2.cpp

daemon/src/video/video_v4l2.h

daemon/src/video/video_v4l2_list.cpp

daemon/src/video/video_v4l2_list.h