CI: fix local docker build

Change-Id: Ibe0f48d3a6a604854a1282b9b0267ba96b3fc255
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 3f3e4e8..f54a995 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,7 +1,10 @@
 image: docker:latest
 
+variables:
+  FF_NETWORK_PER_BUILD: true
 services:
-  - docker:dind
+  - name: docker:dind
+    command: [--dns=127.0.0.11]
 
 stages:
   - build