Fixed growth length not pluralizing
Fixed growth length not pluralizing

Due to bug #22798 this does not work properly for lengths between 1 and
2 hours but is fixed in Django 1.8

emergence-lab/emergence-lab,emergence-lab/emergence-lab,wbg-optronix-lab/emergence-lab,wbg-optronix-lab/emergence-lab,emergence-lab/emergence-lab,wbg-optronix-lab/emergence-lab