Fix unknown constructor

SpigotCore_19/src/de/steamwar/core/ChatWrapper19.java

@@ -40,6 +40,11 @@ public class ChatWrapper19 implements ChatWrapper {
     @Override
     public Object modifyServerDataPacket(Object o) {
         ClientboundServerDataPacket clientboundServerDataPacket = (ClientboundServerDataPacket) o;
-        return new ClientboundServerDataPacket(clientboundServerDataPacket.b().get(),clientboundServerDataPacket.c().get(),true);
+        try{
+            o.getClass().getDeclaredField("c").setBoolean(clientboundServerDataPacket,true);
+        }catch (NoSuchFieldException | IllegalAccessException e) {
+            //ignore
+        }
+        return clientboundServerDataPacket;
     }
 }