Bugfix/pkglists nil pair
This fixes updater failure when user enables no package lists.
Updater fails with error:
ERROR:
runtime: [string "file:////etc/updater/conf.d/turris-pkglists..."]:17: bad argument #1 to 'pairs' (table expected, got nil)
Yeh ups I forgot to test it with no package lists.
Edited by Josef Schlehofer