build codejail worker virtualenvs correctly (#5321)
build codejail worker virtualenvs correctly (#5321)

* use correct branch in codejail worker

* branch name has changed

arbrandes/edx-configuration,appsembler/configuration,stvstnfrd/configuration,arbrandes/edx-configuration,stvstnfrd/configuration,arbrandes/edx-configuration,EDUlib/configuration,edx/configuration,EDUlib/configuration,appsembler/configuration,mitodl/configuration,EDUlib/configuration,stvstnfrd/configuration,EDUlib/configuration,mitodl/configuration,appsembler/configuration,edx/configuration,edx/configuration,appsembler/configuration,edx/configuration,stvstnfrd/configuration,mitodl/configuration,stvstnfrd/configuration,mitodl/configuration,EDUlib/configuration,arbrandes/edx-configuration,arbrandes/edx-configuration