[gtk/doc-chapters-markdown] docs: Use the right python

[Matthias Clasen <matthiasc src gnome org>]

commit ae2e548b4bed446bfbda9cb50c406ac1c5bfae13
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon May 25 18:40:09 2020 -0400

    docs: Use the right python

 docs/reference/gtk/gtk-markdown-to-docbook | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/docs/reference/gtk/gtk-markdown-to-docbook b/docs/reference/gtk/gtk-markdown-to-docbook
index 5830d64d78..f48b556f48 100755
--- a/docs/reference/gtk/gtk-markdown-to-docbook
+++ b/docs/reference/gtk/gtk-markdown-to-docbook
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python3
 #
 # Call pandoc to convert markdown to docbook, then expand gtk-doc
 # abbreviations (|[ ]|, function(), #object, %constant, etc)