fix(signal): tag follows declared version

roles/custom/matrix-bridge-mautrix-signal/defaults/main.yml

@@ -13,7 +13,7 @@ matrix_mautrix_signal_version: 18e006300885e7432f0791211dec77345ae974a2
 
 # See: https://mau.dev/mautrix/signal/container_registry
 matrix_mautrix_signal_docker_image: "{{ matrix_mautrix_signal_docker_image_name_prefix }}mautrix/signal:{{ matrix_mautrix_signal_docker_image_tag }}"
-matrix_mautrix_signal_docker_image_tag: "18e006300885e7432f0791211dec77345ae974a2-{{ matrix_architecture }}"
+matrix_mautrix_signal_docker_image_tag: "{{ 'latest' if matrix_mautrix_signal_version == 'latest' else matrix_mautrix_signal_version + '-' +  matrix_architecture }}"
 matrix_mautrix_signal_docker_image_name_prefix: "{{ 'localhost/' if matrix_mautrix_signal_container_image_self_build else 'dock.mau.dev/' }}"
 matrix_mautrix_signal_docker_image_force_pull: "{{ matrix_mautrix_signal_docker_image.endswith(':latest') }}"