fixes

src/main/kotlin/App.kt

@@ -89,7 +89,7 @@ suspend fun main(args: Array<String>) {
                     val images = settings.makeRequest(i).takeIf { it.isNotEmpty() } ?: break
                     result.addAll(
                         images.filterNot {
-                            chatsUrlsSeen.contains(chatId, it.url)
+                            chatsUrlsSeen.contains(chatId, it.url ?: return@filterNot true)
                         }
                     )
                     i++

src/main/kotlin/ChatSettings.kt

@@ -41,7 +41,7 @@ data class ChatSettings(
 
     suspend fun makeRequest(page: Int): List<BoardImage> {
         return withContext(Dispatchers.IO) {
-            board.search(page, count, query, rating).blocking()
+            board.search(page, count, query, rating).blocking() ?: emptyList()
         }
     }