vagrant: use old configs when updating

Otherwise we may overwrite vagrant-specific settings like
nopassword for sudo.

diff --git a/vagrant/install-on-ubuntu-16.sh b/vagrant/install-on-ubuntu-16.sh
index a4b9ddee8ad993bc8f14c8d7b18fb6e612f9c48b..b40dbce1abaa10add924da4983cc14fff0cc80e9 100755 (executable)
--- a/vagrant/install-on-ubuntu-16.sh
+++ b/vagrant/install-on-ubuntu-16.sh
@@ -19,7 +19,7 @@ export DEBIAN_FRONTEND=noninteractive #DOCS:
 #
 
     sudo apt-get update -qq
-    sudo apt-get -o Dpkg::Options::="--force-confnew" --force-yes -fuy dist-upgrade #DOCS:    sudo apt-get upgrade
+    sudo apt-get -o Dpkg::Options::="--force-confold" --force-yes -fuy dist-upgrade #DOCS:    sudo apt-get upgrade
 
 # Now you can install all packages needed for Nominatim: