Fixing build dependencies

Base image already gives us `build-essential`, but nothing provided
`fakeroot`. :(

.gitlab-ci.yml

@@ -3,7 +3,7 @@ image: containers.ethitter.com:443/docker/images/debian:stretch
 
 before_script:
   - apt-get update
-  - apt-get -y --no-install-recommends install devscripts build-essential lintian
+  - apt-get -y --no-install-recommends install devscripts lintian fakeroot
   - mkdir ../nginx-package-build.orig
 
 package: