don't claim googlehash is there when only qt4 has been found :)

test/CMakeLists.txt

diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 44c0ead..4d29db0 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -66,7 +66,6 @@
 
 find_package(Qt4)
 if(QT4_FOUND)
-  add_definitions("-DEIGEN_GOOGLEHASH_SUPPORT")
   include(${QT_USE_FILE})
   set(EIGEN_TESTED_BACKENDS ${EIGEN_TESTED_BACKENDS} "Qt4 support")
 else(QT4_FOUND)