remove deleted .css files from default.py
remove deleted .css files from default.py

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