fix empty env var values
fix empty env var values

vincent99/ui,rancherio/ui,nrvale0/ui,rancherio/ui,pengjiang80/ui,lvuch/ui,westlywright/ui,rancher/ui,vincent99/ui,pengjiang80/ui,vincent99/ui,pengjiang80/ui,nrvale0/ui,rancherio/ui,westlywright/ui,westlywright/ui,lvuch/ui,lvuch/ui,nrvale0/ui,rancher/ui,rancher/ui