typo fix
Revert "fix for issue #353 : https://github.com/ehynds/jquery-ui-multiselect-widget/issues/353" -- this fix is badly broken as reported in the tracker:

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"At least tests here (not using ASP.NET) show that this change breaks all multiselects on a HTML page which has DOM nodes with relative/absolute positioning as parents to those multiselects -- the multiselect dropdown list pops up way off as the position calculations are based on the assumption that top=0/left=0 is the top/left corner of the /page/, not an (unidentified ~ unknown to this particular multiselect instance) parent DOM node, e.g. some outer DIV.

I don't know what the relation of the edit is to unresponsiveness in ASP.NET as you're just moving the placement of the multiselect menu around, from document root to sibling of multiselect button, so you may need to diagnose your problem further; this change at least visually breaks stuff for others."
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This reverts commit 2b1c48f373b744a24a01f89df6995b1b1ac999d5.