app/matrix: upgrade and migrate to official riot-web container image

Change-Id: I438e5b6e1bfb4a20bb6613904497e1e8a6d86fc5

app/matrix/prod.jsonnet

@@ -17,7 +17,7 @@ local postgres = import "../../kube/postgres.libsonnet";
         storageClassName: "waw-hdd-paranoid-2",
 
         synapseImage: "matrixdotorg/synapse:v1.11.1",
-        riotImage: "bubuntux/riot-web:v1.3.2",
+        riotImage: "vectorim/riot-web:v1.5.13",
         casProxyImage: "registry.k0.hswaw.net/q3k/oauth2-cas-proxy:0.1.4"
     },
 
@@ -201,7 +201,7 @@ local postgres = import "../../kube/postgres.libsonnet";
                             },
                             volumeMounts_: {
                                 config: {
-                                    mountPath: "/etc/riot-web/config.json",
+                                    mountPath: "/app/config.json",
                                     subPath: "config.json",
                                 },
                             },