Igmp Proxy has wrong Api bits in voltha-onos

The issue was that while the .oar of igmpproxy had the correct bits for the API the apps was still showing the old bits while getting activated of a master image of `voltha-onos`, which is the augmented ONOS image with opencord apps.
Yesterday we proved that it was not a build issue of the .oar of igmpproxy by downloading it from sonaytype and having in manually inserted in locally build `volta-onos` images and also manually dropped on run-in ONOS instances.
Also the voltha onos build process was not at fault since the correct .oar with date and timestamp was picked up by the Jenkins build for the voltha-onos release.
The only remaining option (and idea I had this morning) was that somebody else was bringing in the wrong bits. Indeed that was the issue.
It turns out that the kafka app while depending on the correct igmpproxy version (2.1.0-Snapshot) had the previous bits from that version in his .oar.
Apparently how karaf works is that the last app to bring in bits for a certain package and version wins, so with kafka being installed last in the chain it was overriding the correct 2.1.0-Snapshot bits from igmpproxy resulting in the issue of the logger not getting serialised.
The issue is now fixed in the latest voltha-onos. It required adding a patch on Kafka that triggered the build of the artifacts (.oar) and publish on sonatype. After that a new voltha-onos was picking up the latest of both Kafka and igmp-proxy and thus no expiation of serialisation and correct igmprpoxy API bits are present.