ZooKeeper OSGi bundle is missing package import for org.ietf.jgss.

The ZooKeeper build injects OSGi headers into the manifest, but the Import-Package header does not include org.ietf.jgss, which is used by the ZooKeeper code. For applications using ZooKeeper inside an OSGi container, this can cause ClassNotFoundException unless the application adds the missing import to its own OSGi bundle.