Removed unused parameter from DataNode creation (#11976)

Fixes #11958

server/src/main/java/com/vaadin/server/BootstrapHandler.java

         appendMainScriptTagContents(context, builder);
 
         builder.append("//]]>");
-        mainScriptTag.appendChild(
-                new DataNode(builder.toString(), mainScriptTag.baseUri()));
+        mainScriptTag.appendChild(new DataNode(builder.toString()));
         fragmentNodes.add(mainScriptTag);
 
     }