VideoViewer: Fix slider.
VideoViewer: Fix slider.

randi120/Pangolin,mp3guy/Pangolin,wxdzju/Pangolin,mp3guy/Pangolin,wxdzju/Pangolin,renzodenardi/Pangolin,tschmidt23/Pangolin,stevenlovegrove/Pangolin,mp3guy/Pangolin,arpg/Pangolin,tschmidt23/Pangolin,tschmidt23/Pangolin,renzodenardi/Pangolin,stevenlovegrove/Pangolin,arpg/Pangolin,stevenlovegrove/Pangolin,randi120/Pangolin