ReReRevert Permission denied: '/etc/glances/glances.conf' #1403

The snapd version that supports the interface hasn't released to the
stable channel yet, and the Snap Store autoconnection isn't granted,
hold back the patch until both conditions are met.

This reverts commit c904a8a and (parts of) 108dc7b.

snap/snapcraft.yaml

@@ -22,16 +22,11 @@ apps:
       - network-observe
       - physical-memory-observe
       - upower-observe
-      - system-files
       - home
     environment:
       LANG: C.UTF-8
       LC_ALL: C.UTF-8
 
-plugs:
-  system-files:
-    read: [ /etc/glances/glances.conf ]
-
 parts:
   glances:
     plugin: python