Bump exim-relay Docker image tag

The new one is based on Alpine 3.14, instead of Alpine 3.13.

roles/matrix-mailer/defaults/main.yml

@@ -7,7 +7,7 @@ matrix_mailer_container_image_self_build_repository_url: "https://github.com/dev
 matrix_mailer_container_image_self_build_src_files_path: "{{ matrix_mailer_base_path }}/docker-src"
 matrix_mailer_container_image_self_build_version: "{{ matrix_mailer_docker_image.split(':')[1] }}"
 
-matrix_mailer_version: 4.94.2-r0-1
+matrix_mailer_version: 4.94.2-r0-2
 matrix_mailer_docker_image: "{{ matrix_mailer_docker_image_name_prefix }}devture/exim-relay:{{ matrix_mailer_version }}"
 matrix_mailer_docker_image_name_prefix: "{{ 'localhost/' if matrix_mailer_container_image_self_build else matrix_container_global_registry_prefix }}"
 matrix_mailer_docker_image_force_pull: "{{ matrix_mailer_docker_image.endswith(':latest') }}"