Fix click-to-seek for audios which are not spanning the entire canvas (#686)
Fix click-to-seek for audios which are not spanning the entire canvas (#686)

agamemnus/wavesurfer.js,ale-grosselle/wavesurfer.js,ffxsam/wavesurfer.js,ale-grosselle/wavesurfer.js,katspaugh/wavesurfer.js,agamemnus/wavesurfer.js,ffxsam/wavesurfer.js,katspaugh/wavesurfer.js