misc: fix warnings

src/manager.h

src/media/audio/audiorecorder.cpp

src/media/audio/opensl/opensllayer.cpp

src/media/audio/resampler.h

src/media/libav_utils.cpp

src/media/video/androidvideo/video_device_impl.cpp

src/media/video/androidvideo/video_device_monitor_impl.cpp

src/media/video/video_input.cpp

src/ringdht/p2p.cpp

src/ringdht/ringaccount.cpp

src/ringdht/ringaccount.h

src/sip/sipaccountbase.h

src/sip/sipcall.h

src/smartools.cpp

src/upnp/upnp_context.cpp