Small fix to compile ts again

Old code was okay according to mdn: https://developer.mozilla.org/de/docs/Web/API/Document/createTreeWalker
Typescript not liking it: https://github.com/microsoft/TypeScript/issues/33462#issuecomment-912517410

We fine with removing the params as it was optional at all and we set to false

src/javascript/utils/helpers.ts

@@ -43,7 +43,7 @@ export function findTextNodes(baseNode: Node): Array<Node> {
         baseNode = document.documentElement;
     }
 
-    let walker = document.createTreeWalker(baseNode, NodeFilter.SHOW_TEXT, null, false);
+    let walker = document.createTreeWalker(baseNode, NodeFilter.SHOW_TEXT, null);
     let node;
     let results = [];
     while (node = walker.nextNode()) {