Reference PYTHON_NUMPY_INCLUDE_DIRS not PYTHON_NUMPY_INCLUDE_PATH

PYTHON_NUMPY_INCLUDE_PATH was a typo, it should have been
PYTHON_NUMPY_INCLUDE_DIRS.

modules/python/python2/CMakeLists.txt

@@ -6,7 +6,7 @@ set(the_description "The python2 bindings")
 set(MODULE_NAME python2)
 
 set(PYTHON_INCLUDE_PATH ${PYTHON2_INCLUDE_PATH})
-set(PYTHON_NUMPY_INCLUDE_PATH ${PYTHON2_NUMPY_INCLUDE_PATH})
+set(PYTHON_NUMPY_INCLUDE_DIRS ${PYTHON2_NUMPY_INCLUDE_DIRS})
 set(PYTHON_EXECUTABLE ${PYTHON2_EXECUTABLE})
 set(PYTHON_DEBUG_LIBRARIES ${PYTHON2_DEBUG_LIBRARIES})
 set(PYTHON_LIBRARIES ${PYTHON2_LIBRARIES})

modules/python/python3/CMakeLists.txt

@@ -6,7 +6,7 @@ set(the_description "The python3 bindings")
 set(MODULE_NAME python3)
 
 set(PYTHON_INCLUDE_PATH ${PYTHON3_INCLUDE_PATH})
-set(PYTHON_NUMPY_INCLUDE_PATH ${PYTHON3_NUMPY_INCLUDE_PATH})
+set(PYTHON_NUMPY_INCLUDE_DIRS ${PYTHON3_NUMPY_INCLUDE_DIRS})
 set(PYTHON_EXECUTABLE ${PYTHON3_EXECUTABLE})
 set(PYTHON_DEBUG_LIBRARIES ${PYTHON3_DEBUG_LIBRARIES})
 set(PYTHON_LIBRARIES ${PYTHON3_LIBRARIES})