Bug 157722 List group header displays twice when the group begins in a new page.
Description: List group header displays twice when the group begins in a new page. Steps to reproduce: 1. Preview attached report in pdf. 2. See the next page Expected result: One group header. Actual result: Group header displays twice.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/layout/pdf/PDFListGroupLM.java
{
	public PDFListGroupLM( PDFLayoutEngineContext context,
			PDFStackingLM parent, IContent content, IReportItemExecutor executor )
	{
		super( context, parent, content, executor );
	}
	protected IListBandContent getHeader( )
	{
		return (IListBandContent) ( (IGroupContent) content ).getHeader( );
	}
	protected IReportItemExecutor createExecutor( )
	{
		return new ListContainerExecutor( content, executor );
	}
	protected void repeatHeader( )
	{
		if ( isFirst )
		{
			isFirst = false;
			return;
		}
		if ( !isRepeatHeader( ) )
		{
			return;
		}
		IListBandContent band = getHeader( );
		if ( band == null )
		{
			return;
		}