Removes unecessary class on inlines
Removes unecessary class on inlines

This class it's unecessary for grappelli/opps-admin actually,
but when using with other admin such as django-admin-bootstrapped
or adjngo-wpadmin the inline form is hidden.

jeanmask/opps,YACOWS/opps,williamroot/opps,williamroot/opps,jeanmask/opps,williamroot/opps,opps/opps,jeanmask/opps,YACOWS/opps,opps/opps,YACOWS/opps,opps/opps,opps/opps,williamroot/opps,YACOWS/opps,jeanmask/opps