setup.py.in: Try to import setuptools

This way, we can build binary wheels easily if needed

python/setup.py.in

diff --git a/python/setup.py.in b/python/setup.py.in
index fce6382..012eb59 100755
--- a/python/setup.py.in
+++ b/python/setup.py.in
@@ -3,6 +3,12 @@
 # Setup script for libxml2 and libxslt if found
 #
 import sys, os
+
+try:
+    import setuptools
+except ModuleNotFoundError:
+    pass
+
 from distutils.core import setup, Extension
 
 # Below ROOT, we expect to find include, include/libxml2, lib and bin.