Delete git repository URL from imported repository

I recently import a repository from Bitbucket to GitLab and then when I point to I found there’s git repository URL linked to my bitbucket repo URL. I want to remove it, but when I delete this URL and then save the changes, it doesn’t allow me to proceed (because that is required field I guess). But I know it just an optional setting because most of my repository doesn’t have some kind of that git repository URL. Does anyone know how to delete this URL without delete my whole repo and manually push it to GitLab?