make Status.filtered nullable to make some weird api implementations work again (#4426)

closes https://github.com/tuskyapp/Tusky/issues/4424

app/src/main/java/com/keylesspalace/tusky/network/FilterModel.kt

@@ -47,7 +47,7 @@ class FilterModel @Inject constructor() {
             }
         }
 
-        val matchingKind = status.filtered.filter { result ->
+        val matchingKind = status.filtered.orEmpty().filter { result ->
             result.filter.kinds.contains(kind)
         }