FlexRAN Controller repository missing on GitLab

Upon cloning FlexRAN controller repository, I get the following error - It appears the repository is not available at this location:

fatal: repository ‘https://gitlab.eurecom.fr/flexran/flexran-rtc.git/’ not found
Clone of ‘https://gitlab.eurecom.fr/flexran/flexran-rtc.git’ into submodule path ‘controller’ failed