Remove buggy comment.

tinfi/runtime/oo/src/main/java/org/ow2/frascati/tinfi/osoa/CallbackManager.java

@@ -26,7 +26,6 @@ package org.ow2.frascati.tinfi.osoa;
 import java.util.Stack;
 
 import org.osoa.sca.CallableReference;
-import org.ow2.frascati.tinfi.osoa.ConversationImpl;
 
 /**
  * This class manages a thread-local stack of callback callable references.
@@ -51,11 +50,6 @@ public class CallbackManager {
     private static CallbackManager instance = new CallbackManager();
     
     /**
-     * The thread-local stack of conversations. The {@link ConversationImpl}
-     * class is used instead of the {@link org.osoa.sca.Conversation} interface
-     * since some public methods from the class which are not defined in the
-     * interface are needed by code which invokes the current class.
-     * 
      * @since 1.1.1
      */
     private static ThreadLocal<Stack<CallableReference<?>>> tl =