Removed empty sections from 4.0 release notes.
Removed empty sections from 4.0 release notes.

takis/django,rsalmaso/django,monetate/django,manhhomienbienthuy/django,felixxm/django,felixxm/django,pauloxnet/django,django/django,auvipy/django,apollo13/django,takis/django,rsalmaso/django,django/django,rsalmaso/django,django/django,MarkusH/django,blighj/django,dsanders11/django,solarissmoke/django,apollo13/django,blighj/django,shaib/django,manhhomienbienthuy/django,takis/django,felixxm/django,dsanders11/django,shaib/django,pauloxnet/django,takis/django,ghickman/django,solarissmoke/django,monetate/django,monetate/django,ghickman/django,pauloxnet/django,blighj/django,apollo13/django,MarkusH/django,monetate/django,dsanders11/django,django/django,apollo13/django,dsanders11/django,MarkusH/django,auvipy/django,solarissmoke/django,auvipy/django,rsalmaso/django,auvipy/django,blighj/django,ghickman/django,felixxm/django,manhhomienbienthuy/django,manhhomienbienthuy/django,shaib/django,MarkusH/django,ghickman/django,pauloxnet/django,solarissmoke/django,shaib/django