[gtk-osx] Ensure that a string version is passed to python_install_path.

[John Ralls <jralls src gnome org>]

commit d4698cf8aaefabe19cea59e33f9f340b7ca42a4a
Author: John Ralls <jralls ceridwen us>
Date:   Fri Aug 21 20:36:47 2020 -0700

    Ensure that a string version is passed to python_install_path.

 jhbuildrc-gtk-osx | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/jhbuildrc-gtk-osx b/jhbuildrc-gtk-osx
index f618a2b..22edd99 100644
--- a/jhbuildrc-gtk-osx
+++ b/jhbuildrc-gtk-osx
@@ -605,7 +605,8 @@ if 'python3' in modules or 'meta-gtk-osx-python3' in modules:
     module_extra_env['pkg-config'] = {'PYTHON':sys.executable}
 else:
     _python_ver = sys.version_info.major * 10 + sys.version_info.minor
-    _python_install_path = os.path.join(prefix, 'lib', _python_ver, 'site-packages')
+    _python_install_path = os.path.join(prefix, 'lib', str(_python_ver),
+                                        'site-packages')
     append_autogenargs('libxml2',
                        '--with-python-install-dir=' + _python_install_path)
     environ_append('PYTHONPATH', _python_install_path, ':')