[egs] remove duplicated speed-perturbation script in WSJ recipe (kaldi-asr#3995)

Author: freewym

egs/wsj/s5/local/nnet3/run_ivector_common.sh

@@ -77,17 +77,12 @@ fi
 
 
 # high-resolution features and i-vector extractor,
-if [ $stage -le 5 ] && [ -f data/${train_set}_sp_hires/feats.scp ]; then
+if [ $stage -le 4 ] && [ -f data/${train_set}_sp_hires/feats.scp ]; then
   echo "$0: data/${train_set}_sp_hires/feats.scp already exists."
   echo " ... Please either remove it, or rerun this script with stage > 2."
   exit 1
 fi
 
-if [ $stage -le 4 ]; then
-  echo "$0: preparing directory for speed-perturbed data"
-  utils/data/perturb_data_dir_speed_3way.sh data/${train_set} data/${train_set}_sp
-fi
-
 if [ $stage -le 5 ]; then
   echo "$0: creating high-resolution MFCC features"