[FIX] workflow ngram function needeed.

ngram/workflow.py

@@ -6,7 +6,7 @@ from ngram.stop import compute_stop
 from ngram.group import compute_groups
 from gargantext_web.db import get_or_create_node
 from ngram.mapList import compute_mapList
-# from ngram.occurrences import compute_occs
+from ngram.occurrences import compute_occs
 
 from gargantext_web.db import session , Node , NodeNgram
 from admin.utils import WorkflowTracking