Fix javadoc build
Fix javadoc build

We have merge job failing on javadocs, make sure we repair that.

Change-Id: I6c0513bde22aa02ce0685e4b40d4c28ea7d777b4
Signed-off-by: Robert Varga <91ae5aa8c7a9f7e57b701db766e23e544aaa6ae9@pantheon.tech>

opendaylight/yangtools,opendaylight/yangtools