Adapt to CI changes

Change-Id: Icfae1ac294e74db2d36ecc6620f5f12d6ba9a08b
diff --git a/.zuul.yaml b/.zuul.yaml
index 4f65f1e..2462399 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -5,7 +5,7 @@
     post-timeout: 600
     vars:
       prepare_git_submodules: true
-      zuul_work_dir: "{{ zuul.projects['cesnet-gerrit-czechlight/CzechLight/br2-external'].src_dir }}"
+      zuul_work_dir: "{{ zuul.projects[zuul.project.canonical_hostname + '/CzechLight/br2-external'].src_dir }}"
     required-projects: &projects
       - github/buildroot/buildroot
       - CzechLight/dependencies