Update CMakeLists.txt

Author: markmcclain

bindings/python/CMakeLists.txt

@@ -9,7 +9,7 @@ FIND_PACKAGE (PythonInterp ${python_version} REQUIRED)
 IF(PYTHON_VERSION_STRING MATCHES "^([0-9.]+)")
     SET(python_version "${CMAKE_MATCH_1}")
 ELSE()
-    MESSAGE(FATAL_ERROR "PythonInterp version format unknown '${PYTHONINTERP_VERSION_STRING}'")
+    MESSAGE(FATAL_ERROR "PythonInterp version format unknown '${PYTHON_VERSION_STRING}'")
 ENDIF()
 FIND_PACKAGE (PythonLibs ${python_version} REQUIRED)