jetty.xml update use of env vars

Please update jetty.xml file from:

<property name="config" value="${activemq.conf}/jetty-realm.properties"/>

to

<property name="config" value="file:${activemq.conf}/jetty-realm.properties"/>

as already done for activemq.xml.

As far as I understand, on bash it is makes no difference, on zsh I had my broker stuck on:

"${activemq.conf}/jetty-realm.properties not found"

(as if it was not able to make the substitution).