Properly handle filter mapping when registering a servlet filter for tests

  <extension target="org.nuxeo.runtime.server" point="filter">
    <filter context="/">
      <filter-name>NuxeoAuthenticationFilter</filter-name>
      <filter-class&gt;org.nuxeo.ecm.platform.ui.web.auth.NuxeoAuthenticationFilter</filter-class&gt;
      <display-name>Nuxeo Authentication Filter</display-name>
      <filter-mapping>
        <url-pattern>/authentication/*</url-pattern>
        <dispatcher>REQUEST</dispatcher>
        <dispatcher>FORWARD</dispatcher>
      </filter-mapping>
    </filter>
  </extension>

filterMap.addServletName("*");