A NullPointerException is often throw during logout for some users

[syntrydy]

Here is a partial log file:

2018-11-08 15:30:14,158 ERROR [qtp2008017533-13] [org.xdi.oxauth.exception.GlobalExceptionHandler] (GlobalExceptionHandler.java:45) - //opt/jetty-9.3/temp/jetty-localhost-8081-oxauth.war-_oxauth-any-5645578832412827272.dir/webapp/logout.xhtml @8,103 locale="#{language.localeCode}" //opt/jetty-9.3/temp/jetty-localhost-8081-oxauth.war-_oxauth-any-5645578832412827272.dir/webapp/logout.xhtml @8,103 locale="#{language.localeCode}": Error reading 'localeCode' on type org.xdi.oxauth.i18n.LanguageBean
javax.faces.view.facelets.TagAttributeException: //opt/jetty-9.3/temp/jetty-localhost-8081-oxauth.war-_oxauth-any-5645578832412827272.dir/webapp/logout.xhtml @8,103 locale="#{language.localeCode}" //opt/jetty-9.3/temp/jetty-localhost-8081-oxauth.war-_oxauth-any-5645578832412827272.dir/webapp/logout.xhtml @8,103 locale="#{language.localeCode}": Error reading 'localeCode' on type org.xdi.oxauth.i18n.LanguageBean
    at com.sun.faces.facelets.tag.TagAttributeImpl.getObject(TagAttributeImpl.java:358) ~[jsf-impl-2.2.14.jar:2.2.14]

When need to wrap the method getLocaleCode from class org.xdi.oxauth.i18n.LanguageBean with a try catch block.

Note that the root cause of that issue is still unknown.