我使用的是Birt4.4，我的html报告工作正常，但xls和pdf文件抛出Theoutputformatisnotsupported错误org.eclipse.birt.report.engine.api.EngineException:Theoutputformatxslisnotsupported.atorg.eclipse.birt.report.engine.api.impl.EngineTask.setupRenderOption(EngineTask.java:2031)atorg.eclipse.birt.report.engine.api.impl.RunAndRen