Fix C4204 errors while building swig-py with Python 3.9 on Windows.

* subversion/bindings/swig/include/svn_global.swg:
  Add #pragma to make C4204 a warning instead of an errors from Python.h
  in Python 3.9 with Visual Studio.
* subversion/bindings/swig/python/libsvn_swig_py/swigutil_py.c: Ditto.

Reviewed by: brane


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1883570 13f79535-47bb-0310-9956-ffa450edef68
2 files changed