[fix bug 762234] Prevent deleting UserProfiles.
[fix bug 762234] Prevent deleting UserProfiles.

UserProfile objects shouldn't be deleted via the admin, they should
only be deleted by deleting the associated user.

akatsoulas/mozillians,satdav/mozillians,justinpotts/mozillians,justinpotts/mozillians,brian-yang/mozillians,anistark/mozillians,brian-yang/mozillians,brian-yang/mozillians,ChristineLaMuse/mozillians,fxa90id/mozillians,akarki15/mozillians,akatsoulas/mozillians,johngian/mozillians,satdav/mozillians,chirilo/mozillians,fxa90id/mozillians,johngian/mozillians,glogiotatidis/mozillians-new,safwanrahman/mozillians,ChristineLaMuse/mozillians,johngian/mozillians,hoosteeno/mozillians,mozilla/mozillians,glogiotatidis/mozillians-new,safwanrahman/mozillians,safwanrahman/mozillians,justinpotts/mozillians,akatsoulas/mozillians,safwanrahman/mozillians,chirilo/mozillians,akarki15/mozillians,johngian/mozillians,fxa90id/mozillians,brian-yang/mozillians,akarki15/mozillians,akarki15/mozillians,glogiotatidis/mozillians-new,mozilla/mozillians,glogiotatidis/mozillians-new,mozilla/mozillians,justinpotts/mozillians,satdav/mozillians,mozilla/mozillians,anistark/mozillians,chirilo/mozillians,anistark/mozillians,hoosteeno/mozillians,akatsoulas/mozillians,anistark/mozillians,fxa90id/mozillians,chirilo/mozillians,hoosteeno/mozillians,ChristineLaMuse/mozillians,satdav/mozillians,hoosteeno/mozillians