Add missing null check here

proxy/src/main/java/com/velocitypowered/proxy/VelocityServer.java

@@ -256,6 +256,7 @@ public class VelocityServer implements ProxyServer {
 
     @Override
     public void broadcast(Component component) {
+        Preconditions.checkNotNull(component, "component");
         Chat chat = Chat.createClientbound(component);
         for (ConnectedPlayer player : connectionsByUuid.values()) {
             player.getConnection().write(chat);