[tracker/wip/carlosg/portal] ci: Don't install systemd user services

[Carlos Garnacho <carlosg src gnome org>]

commit 8c92c944097a1f3001f31406100302230618fef6
Author: Carlos Garnacho <carlosg gnome org>
Date:   Sun Jun 21 12:06:21 2020 +0200

    ci: Don't install systemd user services
    
    These are not necessary for tests, plus helps on Alpine.

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index e9043c364..e2e7fce77 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -21,7 +21,7 @@ stages:
 
   script:
     - su tracker -c 'mkdir build'
-    - su tracker -c 'cd build; meson .. -Db_lto=true -Db_coverage=true'
+    - su tracker -c 'cd build; meson .. -Db_lto=true -Db_coverage=true -Dsystemd_user_services=false'
     - su tracker -c 'cd build; ninja'
     - |
       # Remove the many "CI_" variables from the environment. Meson dumps the