fix: remove await in non-async init() causing SyntaxError on startup

dropIndex() was called with await inside the non-async init() method,
causing "Unexpected reserved word" and preventing Indiekit from starting.
Use promise .catch() instead since the result isn't needed.

index.js

@@ -952,8 +952,8 @@ export default class ActivityPubEndpoint {
 
     // Drop non-sparse indexes if they exist (created by earlier versions),
     // then recreate with sparse:true so multiple null values are allowed.
-    try { await this._collections.ap_muted.dropIndex("url_1"); } catch {}
+    this._collections.ap_muted.dropIndex("url_1").catch(() => {});
-    try { await this._collections.ap_muted.dropIndex("keyword_1"); } catch {}
+    this._collections.ap_muted.dropIndex("keyword_1").catch(() => {});
     this._collections.ap_muted.createIndex(
       { url: 1 },
       { unique: true, sparse: true, background: true },

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@rmdes/indiekit-endpoint-activitypub",
-  "version": "2.0.15",
+  "version": "2.0.16",
   "description": "ActivityPub federation endpoint for Indiekit via Fedify. Adds full fediverse support: actor, inbox, outbox, followers, following, syndication, and Mastodon migration.",
   "keywords": [
     "indiekit",