[Redmine bugtracker | Report a new issue] Handle the case where calling getUser() on a member returns a null object

Affected version : SquashTM 12.0.0.RELEASE & Redmine bugtracker

Steps to reproduce

Configure a new Redmine project with a project member is a group of anonymous users.

Observed behaviour

Report a new issue is KO with this error:

SquashTM - 3334929 ERROR [http-nio-8080-exec-5] [] --- org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/squash].[dispatcherServlet]: Servlet.service() for servlet [dispatcherServlet] in context with path [/squash] threw exception [Request processing failed: java.lang.NullPointerException: Cannot invoke "com.taskadapter.redmineapi.bean.User.getId()" because "basicUser" is null] with root cause
java.lang.NullPointerException: Cannot invoke "com.taskadapter.redmineapi.bean.User.getId()" because "basicUser" is null