stop accidental selections on progress in ie
stop accidental selections on progress in ie

fixes https://github.com/brion/ogv.js/issues/263

chrislearn/ogv.js,paladox/ogv.js,paladox/ogv.js,paladox/ogv.js,xzf158/ogv.js,chrislearn/ogv.js,chrislearn/ogv.js,paladox/ogv.js,chrislearn/ogv.js,xzf158/ogv.js,xzf158/ogv.js,xzf158/ogv.js,xzf158/ogv.js,paladox/ogv.js,chrislearn/ogv.js