MUC Maximum batch size setting resets on reboot

1. Navigate to *Group Chat -> Group Chat Settings -> conference -> Other Settings*

2. Modify *Maximum batch size* and click on *Save Settings* button.

3. Restart Openfire

4. Return to the same settings page to see the original value

https://github.com/igniterealtime/Openfire/blob/04b5d6ff70ab6b9e1a9c7730a72599e3da53facd/xmppserver/src/main/java/org/jivesoftware/openfire/muc/spi/MultiUserChatServiceImpl.java#L1289 reads from "tasks.log.tasks.log.maxbatchsize"

https://github.com/igniterealtime/Openfire/blob/04b5d6ff70ab6b9e1a9c7730a72599e3da53facd/xmppserver/src/main/java/org/jivesoftware/openfire/muc/spi/MultiUserChatServiceImpl.java#L1377 writes to "tasks.log.maxbatchsize"