fix for java.io.FileNotFoundException: /WEB-INF/retwis.log (No such file or directory) error in Tomcat

During deployment of war file in Tomcat, the application tries to create /WEB-INF/retwis.log due to existing log4j configuration. Following line is commented in log4j.properties to prevent this error: 

log4j.appender.logfile.File=${retwis.root}/WEB-INF/retwis.log