COMP: Update CTK to fix Slicer packaging issue on windows and linux

This commit fixes a regression introduced in r23958 and discussed in [1]

[1] http://slicer-devel.65872.n3.nabble.com/Windows-and-Linux-nightly-packages-tp4033451p4033452.html

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Author: Jean-Christophe Fillion-Robin <jchris.fillionr@kitware.com>
Date: Mon Feb 9 17:02:42 2015 -0500

Ensure PYTHONQT_INSTALL_DIR is not reset in project including CTK

This commit is an attempt to fix a regression introduced by commontk/CTK@fc92239
that was causing the Slicer packaging to fail (mainly because the
variable PYTHONQT_INSTALL_DIR was reset to an empty value after
"find_path" was called in FindPythonQt.cmake)

Note that this a workaround, the issue is being discussed with CMake
developer.

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git-svn-id: http://svn.slicer.org/Slicer4/trunk@23968 3bd1e089-480b-0410-8dfb-8563597acbee