UWS: Fix bug: logical error while trying to get the error that occurred in a UWSThread

import java.util.Set;

import java.util.Vector;

import java.lang.IllegalStateException;

import javax.servlet.ServletOutputStream;

import uws.UWSException;

import uws.UWSExceptionFactory;

import uws.UWSToolBox;

import uws.job.manager.ExecutionManager;

import uws.job.parameters.UWSParameters;

import uws.job.serializer.UWSSerializer;

import uws.job.user.JobOwner;

import uws.service.UWS;

	 * @return	The error which interrupts the thread or <i>null</i> if there was no error or if the job is still running.

	 */

	public final UWSException getWorkError(){

		return (thread == null && !thread.isAlive()) ? null : thread.getError();

		return (thread == null || !thread.isAlive()) ? null : thread.getError();

	}

	/* ************* */