Fix: refactor after upgrade to eucalyptus
Fix: refactor after upgrade to eucalyptus

`_ccx_students_enrrolling_center` was replaced by `ccx_students_enrrolling_center`. Last one requires **coach** param
Livit/Livit.Learn.EdX,Livit/Livit.Learn.EdX,Livit/Livit.Learn.EdX,Livit/Livit.Learn.EdX