Attempt to change wrong slash in cmake for Windows.

cmake/generic/modules/FindNumpy.cmake

@@ -44,6 +44,9 @@ else()
     endif()
 endif()
 
+if(WIN32)
+  STRING(REGEX REPLACE "\\\\" "/" NUMPY_INCLUDE_DIR ${NUMPY_INCLUDE_DIR})
+endif()
 
 MARK_AS_ADVANCED (NUMPY_INCLUDE_DIR)
 MARK_AS_ADVANCED (NUMPY_VERSION_STRING)