Create the lag display panel before adding it.

It works better this way.

Change-Id: I20470a7d5c12b52798bdab9bd5f9a385d140443c
Fixes-Issue: CLIENT-441
Reviewed-on: http://gerrit.dmdirc.com/3155
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>