Update MongoDB driver

lib/cache.ts

@@ -30,6 +30,7 @@ export async function connect(): Promise<void> {
   const MONGODB_CONNECTION_URL = "" + config.get("MONGODB_CONNECTION_URL");
   clientPromise = MongoClient.connect(MONGODB_CONNECTION_URL, {
     useNewUrlParser: true,
+    useUnifiedTopology: true,
   });
   const db = (await clientPromise).db();
   mongoCollection = db.collection("cache");

lib/db.ts

@@ -50,6 +50,7 @@ export let client: MongoClient;
 export async function connect(): Promise<void> {
   clientPromise = MongoClient.connect("" + get("MONGODB_CONNECTION_URL"), {
     useNewUrlParser: true,
+    useUnifiedTopology: true,
   });
 
   client = await clientPromise;

lib/ui/db.ts

@@ -46,7 +46,7 @@ function getClient(): Promise<MongoClient> {
       const CONNECTION_URL = "" + config.get("MONGODB_CONNECTION_URL");
       MongoClient.connect(
         CONNECTION_URL,
-        { useNewUrlParser: true },
+        { useNewUrlParser: true, useUnifiedTopology: true },
         (err, client) => {
           if (err) return void reject(err);
           ensureIndexes(client);