[gnome-shell] ci: Rename Dockerfile

[verdre <jonasd src gnome org>]

commit e7512fcd790fdde4b7f929509cc72cc71519ff7a
Author: Florian Müllner <fmuellner gnome org>
Date:   Sat Apr 4 02:22:00 2020 +0200

    ci: Rename Dockerfile
    
    Our primary image now comes from mutter, so the default Dockerfile
    name is free for our JS image.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1177

 .gitlab-ci/{Dockerfile.extension-ci => Dockerfile} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
---
diff --git a/.gitlab-ci/Dockerfile.extension-ci b/.gitlab-ci/Dockerfile
similarity index 100%
rename from .gitlab-ci/Dockerfile.extension-ci
rename to .gitlab-ci/Dockerfile