message: fix(localization): pybabel doesn't extract plural forms from frontend
diff: @@ -45,7 +45,7 @@ pybabel extract \
  --sort-output \
  --copyright-holder=Superset \
  --project=Superset \
  - -k _ -k __ -k t -k tn -k tct .
  + -k _ -k __ -k t -k tn:1,2 -k tct .
  cat $LICENSE_TMP superset/translations/messages.pot > messages.pot.tmp \
  && mv messages.pot.tmp superset/translations/messages.pot
  