6.4.3 MOBILE; Opacity slider does not work 

on iOS7.02 iphone 4s

and eg http://mf-geoadmin30i.bgdi.admin.ch/main/prod/mobile.html?lang=de&X=177628.18&Y=656863.37&zoom=12&topic=ech&bgLayer=ch.swisstopo.pixelkarte-farbe&mobile=true&layers=ch.bfs.arealstatistik-1997,ch.swisstopo.fixpunkte-agnes

opacity in selction can not be changed (slider does not move)
related to ?
https://github.com/geoadmin/mf-geoadmin3/pull/486