SFragment: open browser if attachment type is unknown

app/src/main/java/com/keylesspalace/tusky/fragment/SFragment.java

@@ -426,9 +426,7 @@ public abstract class SFragment extends BaseFragment implements Injectable {
                 break;
             }
             case UNKNOWN: {
-                /* Intentionally do nothing. This case is here is to handle when new attachment
-                 * types are added to the API before code is added here to handle them. So, the
-                 * best fallback is to just show the preview and ignore requests to view them. */
+                onViewUrl(active.getUrl());
                 break;
             }
         }