jetty-osgi/jetty-osgi-boot/jettyhome/etc/jetty-deployer.xml

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

<Configure id="Server" class="org.eclipse.jetty.server.Server">

    <!-- =========================================================== -->
    <!-- Configure the deployment manager                            -->
    <!-- =========================================================== -->
    <Call name="addBean">
      <Arg>
        <New id="DeploymentManager" class="org.eclipse.jetty.deploy.DeploymentManager">
          <Set name="contexts">
            <Ref refid="Contexts" />
          </Set>
          <Call name="setContextAttribute">
            <Arg>org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern</Arg>
            <Arg>.*/jsp-api-[^/]*\.jar$|.*/jsp-[^/]*\.jar$</Arg>
          </Call>
        </New>
      </Arg>
    </Call>

</Configure>