Fix disappearing messages when no history is loaded.

src/net/java/sip/communicator/impl/gui/main/chat/ChatPanel.java

@@ -545,8 +545,6 @@ else if(o instanceof ChatRoomMessageReceivedEvent)
             conversationPanel.appendMessageToEnd(historyString);
         }
 
-        isHistoryLoaded = true;
-
         getChatWindow().getMainToolBar()
             .changeHistoryButtonsState(this);
     }
@@ -1292,6 +1290,8 @@ public void finished()
                     processHistory(historyList, escapedMessageID);
                 }
 
+                isHistoryLoaded = true;
+
                 // Add incoming events accumulated while the history was loading
                 // at the end of the chat.
                 addIncomingEvents();