GDC: Closes #2030. Fixed JS errors in IE11 workaround when destroying a chart

* git@github.com:highslide-software/highcharts.com.git
  commit e5ab5df06ae66a906b1f36b93211ed158e1c02c8
  Author: Torstein Hønsi <torstein@highsoft.com>
  Date:   Thu Dec 12 09:30:56 2013 +0100

  Fixed JS errors in IE11 workaround when destroying a chart in the same thread as creating it. Closes #2030.