revert change to env/custom.sh 
revert change to env/custom.sh 

accidental include in https://github.com/cBioPortal/cbioportal-frontend/pull/3511

Former-commit-id: fa0ba2f838be6728d9901d96e5eabb67afd98c44
alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend