[Windows] Expunge pthreads2VC.dll from DumpRenderTree Project
https://bugs.webkit.org/show_bug.cgi?id=115889

Patch by Brent Fulgham <bfulgham@webkit.org> on 2013-05-14
Reviewed by Benjamin Poulain.

* DumpRenderTree/DumpRenderTree.vcxproj/DumpRenderTree/DumpRenderTreeCommon.props:
* DumpRenderTree/win/DumpRenderTreeCommon.vsprops:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@150095 268f45cc-cd09-0410-ab3c-d52691b4dbfc