Do not echo back messages in conversations.

src/main/java/com/alttd/playershops/conversation/ConversationManager.java

@@ -26,6 +26,7 @@ public class ConversationManager implements ConversationAbandonedListener {
                 .addConversationAbandonedListener(this)
                 .withEscapeSequence("cancel");
         conversation = conversationFactory.buildConversation(player);
+        conversation.setLocalEchoEnabled(false); // why is this not in the builder
         conversation.begin();
     }