Cannot change the origin when sharing a desktop region in a conference

[jitsi-jenkins]

When the focus of a conference shares a region of the desktop and tries to move the window, the following exceptions occur:

org.jitsi.impl.neomedia.device.VideoTranslatorMediaDevice cannot be cast to org.jitsi.impl.neomedia.device.MediaDeviceImpl
java.lang.ClassCastException: org.jitsi.impl.neomedia.device.VideoTranslatorMediaDevice cannot be cast to org.jitsi.impl.neomedia.device.MediaDeviceImpl
    at org.jitsi.impl.neomedia.VideoMediaStreamImpl.movePartialDesktopStreaming(VideoMediaStreamImpl.java:986)
    at net.java.sip.communicator.impl.protocol.sip.OperationSetDesktopStreamingSipImpl.movePartialDesktopStreaming(OperationSetDesktopStreamingSipImpl.java:306)

And:

org.jitsi.impl.neomedia.device.VideoTranslatorMediaDevice cannot be cast to org.jitsi.impl.neomedia.device.MediaDeviceImpl
java.lang.ClassCastException: org.jitsi.impl.neomedia.device.VideoTranslatorMediaDevice cannot be cast to org.jitsi.impl.neomedia.device.MediaDeviceImpl
    at org.jitsi.impl.neomedia.MediaServiceImpl.getOriginForDesktopStreamingDevice(MediaServiceImpl.java:1336)
    at net.java.sip.communicator.impl.protocol.sip.OperationSetDesktopStreamingSipImpl.getOriginForMediaDevice(OperationSetDesktopStreamingSipImpl.java:338)
    at net.java.sip.communicator.impl.protocol.sip.OperationSetDesktopStreamingSipImpl.setLocalVideoAllowed(OperationSetDesktopStreamingSipImpl.java:213)

(Issue migrated from https://trac.jitsi.org/ticket/1210)