Fix python3 paths

development path accidentally checked in

example/aitf-data-for-run

-#!  /home/adesmet/csppfetch/example/venv/bin/python3
 #! /usr/bin/python3
 
 # System modules

example/aitf-update-cache

-#!  /home/adesmet/csppfetch/example/venv/bin/python3
+#! /usr/bin/python3
 
 # System modules
 import os