dnscrypt-proxy vmtest: more specific waitForUnit

The test sometimes times out waiting for multi-user.target; this
should be more robust.

Changed files
+3 -2
nixos
+3 -2
nixos/tests/dnscrypt-proxy.nix
···
testScript = ''
$client->start;
-
$client->waitForUnit("multi-user.target");
+
$client->waitForUnit("sockets.target");
+
$client->waitForUnit("dnsmasq");
# The daemon is socket activated; sending a single ping should activate it.
$client->execute("${pkgs.iputils}/bin/ping -c1 example.com");
-
$client->succeed("systemctl is-active dnscrypt-proxy.service");
+
$client->succeed("systemctl is-active dnscrypt-proxy");
'';
})