Fix: Build error with MSVC

rB4f81b4b4ce29 mistakenly left out the changes
to platform_win32.cmake causing a linker error
when WITH_GMP and WITH_TBB_MALLOC_PROXY were on.

build_files/cmake/platform/platform_win32.cmake

@@ -679,6 +679,7 @@ if(WITH_TBB)
   set(TBB_INCLUDE_DIR ${LIBDIR}/tbb/include)
   set(TBB_INCLUDE_DIRS ${TBB_INCLUDE_DIR})
   if(WITH_TBB_MALLOC_PROXY)
+    set(TBB_MALLOC_LIBRARIES optimized ${LIBDIR}/tbb/lib/tbbmalloc.lib debug ${LIBDIR}/tbb/lib/tbbmalloc_debug.lib)
     add_definitions(-DWITH_TBB_MALLOC)
   endif()
 endif()