Re-enable use of ActiveMQ in Karaf version 3

As described in

http://karaf.922171.n3.nabble.com/Karaf-3-0-6-upgrading-to-latest-ActiveMQ-fails-td4046639.html
and
http://activemq.2283324.n4.nabble.com/Unresolved-constraint-in-bundle-activemq-karaf-when-trying-to-upgrade-to-AMQ-5-13-2-td4710202.html

unfortunately recent ActiveMQ versions can no longer be deployed in Karaf 3.x
This is due to pulling in a hard dependency to org.osgi.framework version 1.8 in the activemq-karaf Jar/bundle.

It can be solved by configuring a version range in the activemq-karaf/pom.xml
Very similar to what is already done:

            <Import-Package>
              org.apache.felix.gogo.commands,
              org.apache.karaf.shell.console;version="[2,4)",
              org.apache.karaf.shell.console.commands;version="[2,4)",
              *
            </Import-Package>

add a line

              org.osgi.framework;version="[1.7,2)",

I fully understand the need to go to Karaf 4 for GUI integration, etc. But if one only needs core ActiveMQ, then it should still be possible to deploy it in Karaf 3.x.