Add logout_redirect_url var and option templating for matrix element client

roles/custom/matrix-client-element/defaults/main.yml

@@ -318,3 +318,5 @@ matrix_client_element_location_sharing_map_style_content_sources_localsource_til
 # matrix_client_element_location_sharing_map_style_content_sources_localsource_attribution: "&copy; <a href=\"https://www.openstreetmap.org/copyright\" target=\"_blank\">OpenStreetMap</a> contributors"
 # Leave blank, if map does not require attribution.
 matrix_client_element_location_sharing_map_style_content_sources_localsource_attribution: ""
+
+matrix_client_element_logout_redirect_url: ''

roles/custom/matrix-client-element/templates/config.json.j2

@@ -40,6 +40,9 @@
 	{% if matrix_client_element_location_sharing_enabled %}
 	"map_style_url": {{ matrix_client_element_map_style_url | to_json }},
 	{% endif %}
+	{% if matrix_client_element_logout_redirect_url != '' %}
+	"logout_redirect_url": "{{ matrix_client_element_logout_redirect_url }}",
+	{% endif %}
 	"branding": {
 		"auth_footer_links": {{ matrix_client_element_branding_auth_footer_links | to_json }},
 		"auth_header_logo_url": {{ matrix_client_element_branding_auth_header_logo_url | to_json }},