Remove incorrect copyright header from Google

My Eclipse was misconfigured years ago and wrote this header
on ChoicePointFrame when the class was refactored out of other
code that came from the original Prolog Cafe. Google never had
the intention of reserving all rights; the file is under the dual
GPL+EPL license used by the project.

Change-Id: I165c6710bfd6cb47c8816799ead574de0d8c8139
diff --git a/src/lang/ChoicePointFrame.java b/src/lang/ChoicePointFrame.java
index 908586a..ba33382 100644
--- a/src/lang/ChoicePointFrame.java
+++ b/src/lang/ChoicePointFrame.java
@@ -1,5 +1,3 @@
-// Copyright 2011 Google Inc. All Rights Reserved.
-
 package com.googlecode.prolog_cafe.lang;
 
 /**