Use https for the Ubuntu repo same as salt-bootstrap.

Signed-off-by: Rene Jochum <rene@jochums.at>

salt/pkgrepo/ubuntu/init.sls

@@ -1,5 +1,5 @@
 saltstack-pkgrepo:
   pkgrepo.managed:
-    - name: deb http://repo.saltstack.com/apt/ubuntu/{{ grains['lsb_distrib_release'] }}/amd64/latest {{ grains['lsb_distrib_codename'] }} main
+    - name: deb https://repo.saltstack.com/apt/ubuntu/{{ grains['lsb_distrib_release'] }}/amd64/latest {{ grains['lsb_distrib_codename'] }} main
     - file: /etc/apt/sources.list.d/saltstack.list
     - key_url: https://repo.saltstack.com/apt/ubuntu/{{ grains['lsb_distrib_release'] }}/amd64/latest/SALTSTACK-GPG-KEY.pub