Switch synapse-admin docker image to a working one

roles/custom/matrix-synapse-admin/defaults/main.yml

@@ -1,6 +1,9 @@
 ---
 # matrix-synapse-admin is a web UI for mananging the Synapse Matrix server
 # Project source code URL: https://github.com/Awesome-Technologies/synapse-admin
+# Pre-built docker images are from https://gitlab.com/etke.cc/synapse-admin, reasons:
+# - arm64 and amd64 images
+# - fixed public url issue (added in 0.8.6)
 
 matrix_synapse_admin_enabled: true
 
@@ -10,8 +13,8 @@ matrix_synapse_admin_container_image_self_build_repo: "https://github.com/Awesom
 matrix_synapse_admin_docker_src_files_path: "{{ matrix_base_data_path }}/synapse-admin/docker-src"
 
 matrix_synapse_admin_version: 0.8.6
-matrix_synapse_admin_docker_image: "{{ matrix_synapse_admin_docker_image_name_prefix }}awesometechnologies/synapse-admin:{{ matrix_synapse_admin_version }}"
-matrix_synapse_admin_docker_image_name_prefix: "{{ 'localhost/' if matrix_synapse_admin_container_image_self_build else matrix_container_global_registry_prefix }}"
+matrix_synapse_admin_docker_image: "{{ matrix_synapse_admin_docker_image_name_prefix }}etke.cc/synapse-admin:{{ matrix_synapse_admin_version }}"
+matrix_synapse_admin_docker_image_name_prefix: "{{ 'localhost/' if matrix_synapse_admin_container_image_self_build else 'registry.gitlab.com/' }}"
 matrix_synapse_admin_docker_image_force_pull: "{{ matrix_synapse_admin_docker_image.endswith(':latest') }}"
 
 # A list of extra arguments to pass to the container