component/zlib: Fix zlib download

zlib source url has been moved. Please see issue
https://github.com/madler/zlib/issues/649 for reference.
4 jobs for 1.0
Status Job ID Name Coverage
  External
passed ERP5.StandaloneDeploymentScriptTest-Debian.Buster

passed SlapOS-Master.StandaloneDeploymentScriptTest-Debian.Buster

failed SlapOS-Master.StandaloneDeploymentScriptTest-Debian.Stretch

passed Wendelin.StandaloneDeploymentScriptTest-Debian.Stretch