Need null check here, getDelta() may return null per the API.

java.lang.NullPointerException
	at org.eclipse.egit.core.synchronize.GitSubscriberMergeContext$2.resourceChanged(GitSubscriberMergeContext.java:68)
	at org.eclipse.core.internal.events.NotificationManager$1.run(NotificationManager.java:291)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
	at org.eclipse.core.internal.events.NotificationManager.notify(NotificationManager.java:285)
	at org.eclipse.core.internal.events.NotificationManager.handleEvent(NotificationManager.java:249)
	at org.eclipse.core.internal.resources.Workspace.broadcastEvent(Workspace.java:390)
	at org.eclipse.core.internal.resources.Project.close(Project.java:199)
	at org.eclipse.ui.actions.CloseResourceAction.invokeOperation(CloseResourceAction.java:129)
	at org.eclipse.ui.actions.WorkspaceAction.execute(WorkspaceAction.java:164)
	at org.eclipse.ui.actions.WorkspaceAction$2.runInWorkspace(WorkspaceAction.java:485)
	at org.eclipse.core.internal.resources.InternalWorkspaceJob.run(InternalWorkspaceJob.java:38)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)