Update path to signald Dockerfile

roles/matrix-bridge-mautrix-signal/tasks/setup_install.yml

@@ -70,7 +70,7 @@
     force_source: "{{ matrix_mautrix_signal_daemon_git_pull_results.changed if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
     force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mautrix_signal_daemon_git_pull_results.changed }}"
     build:
-      dockerfile: Dockerfile
+      dockerfile: Containerfile
       path: "{{ matrix_mautrix_signal_daemon_docker_src_files_path }}"
       pull: true
   when: "matrix_mautrix_signal_daemon_container_image_self_build|bool"