FindPythonInterp: fix version component variables for Python 1.4 (#15275)

This bug was introduced in "FindPythonInterp: rework the version detection"
7d6db93de9ffc6e6092fa722aaf9c057dadcd634.

Modules/FindPythonInterp.cmake

@@ -148,8 +148,8 @@ if(PYTHON_EXECUTABLE)
             # this is older.
             set(PYTHON_VERSION_STRING "1.4")
             set(PYTHON_VERSION_MAJOR "1")
-            set(PYTHON_VERSION_MAJOR "4")
-            set(PYTHON_VERSION_MAJOR "0")
+            set(PYTHON_VERSION_MINOR "4")
+            set(PYTHON_VERSION_PATCH "0")
         endif()
     endif()
     unset(_PYTHON_VERSION_RESULT)