increment messageId

src/plugins/monitoring/src/java/org/jivesoftware/openfire/archive/ConversationManager.java

@@ -986,9 +986,12 @@ public class ConversationManager implements Startable, ComponentEventListener{
 
 					pstmt = con.prepareStatement(INSERT_MESSAGE);
 					ArchivedMessage message;
+					
+					int msgCount = getArchivedMessageCount();
+					
 					int count = 0;
 					while ((message = messageQueue.poll()) != null) {
-						pstmt.setInt(1, getArchivedMessageCount());
+						pstmt.setInt(1, ++msgCount);
 						pstmt.setLong(2, message.getConversationID());
 						pstmt.setString(3, message.getFromJID().toBareJID());
 						pstmt.setString(4, message.getFromJID().getResource());