stop releasing fabric virt bundles

There are a couple of bundles (with same version) that are released each time we do a release build

http://repo.fusesource.com/nexus/content/repositories/releases-to-central/org/fusesource/fabric/virt/bundles/org.fusesource.fabric.virt.bundles.jna/3.3.0_1/org.fusesource.fabric.virt.bundles.jna-3.3.0_1.jar
http://repo.fusesource.com/nexus/content/repositories/releases-to-central/org/fusesource/fabric/virt/bundles/org.fusesource.fabric.virt.bundles.jna/3.3.0_1/org.fusesource.fabric.virt.bundles.jna-3.3.0_1.pom
http://repo.fusesource.com/nexus/content/repositories/releases-to-central/org/fusesource/fabric/virt/bundles/org.fusesource.fabric.virt.bundles.libvirt/0.4.6_1/org.fusesource.fabric.virt.bundles.libvirt-0.4.6_1.jar
http://repo.fusesource.com/nexus/content/repositories/releases-to-central/org/fusesource/fabric/virt/bundles/org.fusesource.fabric.virt.bundles.libvirt/0.4.6_1/org.fusesource.fabric.virt.bundles.libvirt-0.4.6_1.pom

we should modify the build to exclude these since these are in central already.