examples: python: print into stderr

https://mail.gnome.org/archives/networkmanager-list/2015-March/msg00024.html

Signed-off-by: Petr Vorel <petr.vorel@gmail.com>

examples/python/gi/update-ip4-method.py

@@ -80,6 +80,6 @@ if __name__ == "__main__":
             c.commit_changes(True, None)
             print("The connection profile has been updated.")
         except Exception, e:
-            print("Error: %s" % e)
+            sys.stderr.write("Error: %s\n" % e)
         break