Fix search extraction

Author: litetex

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/invidious/extractors/InvidiousSearchExtractor.java

@@ -46,6 +46,10 @@ public InfoItemsPage<InfoItem> getInitialPage() throws IOException, ExtractionEx
     public InfoItemsPage<InfoItem> getPage(
             final Page page
     ) throws IOException, ExtractionException {
+        if (results == null) {
+            return InfoItemsPage.emptyPage();
+        }
+
         int pageNumber = 1;
         try {
             if (page.getId() != null) {