(trunk/babel/s5b) Changing the --zero-if-disjoint flag to --drop-frames flag...

(trunk/babel/s5b) Changing the --zero-if-disjoint flag to --drop-frames flag during the call of train_mmi_sgmm2.sh

git-svn-id: https://svn.code.sf.net/p/kaldi/code/trunk@3426 5e6a8d80-dfce-4ca6-a32a-6e07a63d50c8