Add missing overrides for vpriv debstuff groups

dotfiles/config/mkittool/debstuff.ini

     uri_pattern = ~/vcs.jats/%s
 
 [debstuff.def.group.vpriv]
+    branch = master
     uri_pattern = ~/st/vcs.private/%s
+    storage_root = ~/pals/vornet-private/deb
 
 [debstuff.def.group.vscratch]
     branch = devel