<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE10" />
I just found a temporary fix for this.
Open manager/templates/default/header.tpl and add to the head-section of the document:
<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE10">
This way IE10 will be emulated and the insert link function works again.