ConnectionFactory and ActiveMQCamelComponent should default to the right port if on OpenShift

our default is localhost:61616 out of the box. Though this doesn't work on OpenShift - where we default to using 31313 so its in the allowable range.

When Java is running in the openshift cartridge we can easily tell using an environment variable; so it'd be nice if we automatically checked for that and defaulted to it out of the box. Then a vanilla ActiveMQ connection factory or camel component would automatically just use the right port on openshift. (Then if we're using, say, a local broker or gateway, it'd just work).

Here's where the port/env var gets defined:
https://github.com/jboss-fuse/fuse-openshift-cartridge/blob/master/metadata/manifest.yml#L94

So we'd just need to check for the env value of OPENSHIFT_FUSE_AMQ_PORT and use that if its defined otherwise default to 61616