Prevent NPE being thrown on recently updated dashboard.

2010-03-24 19:26:58,469 ERROR [http-9823-1] [atlassian.confluence.pages.DefaultAttachmentManager] getAttachmentData Could not find data for attachment: Attachment: Options.GIF v.1 (92241928) nwilkins - java.io.FileNotFoundException: /home/user/confluence/data/attachments/ver003/177/12/262177/134/78/92078134/92241928 (No such file or directory)
...
2010-03-24 19:26:58,473 ERROR [http-9823-1] [renderer.v2.components.MacroRendererComponent] processMacro Unexpected error formatting macro: recently-updated-dashboard
 -- referer: http://HOST:PORT/admin/search-indexes.action | url: /dashboard.action | userName: admin | action: dashboard
java.lang.NullPointerException
	at com.atlassian.core.util.ImageInfo.read(ImageInfo.java:1228)
	at com.atlassian.core.util.ImageInfo.check(ImageInfo.java:249)
	at com.atlassian.confluence.pages.attachments.DefaultImageDetailsManager.buildImageDetails(DefaultImageDetailsManager.java:87)
	at com.atlassian.confluence.pages.attachments.DefaultImageDetailsManager.createImageDetails(DefaultImageDetailsManager.java:56)
	at com.atlassian.confluence.pages.attachments.DefaultImageDetailsManager.getImageDetails(DefaultImageDetailsManager.java:48)
	at com.atlassian.confluence.pages.thumbnail.DefaultThumbnailManager.getThumbnailInfo(DefaultThumbnailManager.java:132)
	at com.atlassian.confluence.pages.thumbnail.DefaultThumbnailManager.getThumbnailInfo(DefaultThumbnailManager.java:127)
	at com.atlassian.confluence.util.DefaultThumbnailInfoFactory.getThumbnailInfo(DefaultThumbnailInfoFactory.java:22)
	at com.atlassian.confluence.plugins.macros.dashboard.RecentlyUpdatedContentMacro.addThumbnailData(RecentlyUpdatedContentMacro.java:406)
	at com.atlassian.confluence.plugins.macros.dashboard.RecentlyUpdatedContentMacro.getChangeSets(RecentlyUpdatedContentMacro.java:357)
	at com.atlassian.confluence.plugins.macros.dashboard.RecentlyUpdatedContentMacro.execute(RecentlyUpdatedContentMacro.java:303)
	at com.atlassian.confluence.macro.ContentFilteringMacro.execute(ContentFilteringMacro.java:106)
	at com.atlassian.renderer.v2.macro.ResourceAwareMacroDecorator.execute(ResourceAwareMacroDecorator.java:51)
	at com.atlassian.renderer.v2.components.MacroRendererComponent.executeMacro(MacroRendererComponent.java:188)
	at com.atlassian.renderer.v2.components.MacroRendererComponent.processMacro(MacroRendererComponent.java:154)
	at com.atlassian.renderer.v2.components.MacroRendererComponent.makeMacro(MacroRendererComponent.java:58)
	at com.atlassian.renderer.v2.components.WikiContentRendererHandler.handleMacro(WikiContentRendererHandler.java:18)
	at com.atlassian.renderer.v2.WikiMarkupParser.makeMacro(WikiMarkupParser.java:120)
	at com.atlassian.renderer.v2.WikiMarkupParser.handlePotentialMacro(WikiMarkupParser.java:105)
	at com.atlassian.renderer.v2.WikiMarkupParser.parse(WikiMarkupParser.java:60)
	at com.atlassian.renderer.v2.components.MacroRendererComponent.render(MacroRendererComponent.java:43)
	at com.atlassian.renderer.v2.V2Renderer.render(V2Renderer.java:53)
	at com.atlassian.renderer.v2.plugin.PluggableV2Renderer.render(PluggableV2Renderer.java:30)
	at com.atlassian.renderer.v2.V2RendererFacade.convertWikiToXHtml(V2RendererFacade.java:57)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:585)
	at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:304)
...