Upgrade riot-web (1.6.5 -> 1.6.6)

roles/matrix-riot-web/defaults/main.yml

@@ -2,7 +2,7 @@ matrix_riot_web_enabled: true
 
 matrix_riot_web_container_image_self_build: false
 
-matrix_riot_web_docker_image: "vectorim/riot-web:v1.6.5"
+matrix_riot_web_docker_image: "vectorim/riot-web:v1.6.6"
 matrix_riot_web_docker_image_force_pull: "{{ matrix_riot_web_docker_image.endswith(':latest') }}"
 
 matrix_riot_web_data_path: "{{ matrix_base_data_path }}/riot-web"