LDADriver not being initialised properly

all the clustering drivers under o.a.m.clustering, eg CanopyDriver, DirichletDriver, FuzzyKMeansDriver etc
are bootstrapped in main() with ToolRunner

for some reason o.a.m.clustering.lda.LDADriver wasn't being boostrapped like this so job conf was null

found while trying to run LDADriver as part of examples/bin/build-reuters.sh