Fix: drop unusable liblttng-ust-java.so

Fix: drop unusable liblttng-ust-java.so

There is no java class installed onto the system anyway, so it was
dependent on having access to the build tree to use it. And
documentation only sits in the build tree, so instead of installing a
.so that cannot be used, and is not documented, remove it from the
package for 2.0.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>