Add an empty custom.css to cope with THEME_URLS being empty
Add an empty custom.css to cope with THEME_URLS being empty

Br3nda/alaveteli,codeforcroatia/alaveteli,andreicristianpetcu/alaveteli_old,petterreinholdtsen/alaveteli,codeforcroatia/alaveteli,andreicristianpetcu/alaveteli_old,andreicristianpetcu/alaveteli_old,Br3nda/alaveteli,andreicristianpetcu/alaveteli,TEDICpy/QueremoSaber,nzherald/alaveteli,TEDICpy/QueremoSaber,TEDICpy/QueremoSaber,codeforcroatia/alaveteli,datauy/alaveteli,nzherald/alaveteli,Br3nda/alaveteli,andreicristianpetcu/alaveteli,Br3nda/alaveteli,obshtestvo/alaveteli-bulgaria,4bic/alaveteli,datauy/alaveteli,TEDICpy/QueremoSaber,4bic/alaveteli,obshtestvo/alaveteli-bulgaria,andreicristianpetcu/alaveteli_old,petterreinholdtsen/alaveteli,datauy/alaveteli,TEDICpy/QueremoSaber,obshtestvo/alaveteli-bulgaria,Br3nda/alaveteli,nzherald/alaveteli,obshtestvo/alaveteli-bulgaria,obshtestvo/alaveteli-bulgaria,4bic/alaveteli,andreicristianpetcu/alaveteli_old,4bic/alaveteli,nzherald/alaveteli,nzherald/alaveteli,andreicristianpetcu/alaveteli,andreicristianpetcu/alaveteli,andreicristianpetcu/alaveteli,petterreinholdtsen/alaveteli,petterreinholdtsen/alaveteli,petterreinholdtsen/alaveteli,4bic/alaveteli,codeforcroatia/alaveteli