jetty-server/src/main/config/etc/jetty-proxy-protocol.xml

<?xml version="1.0"?><!DOCTYPE Configure PUBLIC "-//Jetty//Configure//EN" "http://www.eclipse.org/jetty/configure_9_3.dtd">

<Configure id="httpConnector" class="org.eclipse.jetty.server.ServerConnector">
  <Call name="addFirstConnectionFactory">
    <Arg>
      <New class="org.eclipse.jetty.server.ProxyConnectionFactory"/>
    </Arg>
  </Call>
</Configure>