stack/slapos: version up passlib 1.7.4

should fix crypt issues with python 3.9
Status Job ID Name Coverage
  External
running Cloudooo.UnitTest-Master

17347:18:43

running ERP5.StandaloneDeploymentScriptTest-Debian.Buster.Master

17347:18:24

running SlapOS.Eggs.UnitTest-Jerome.Python2

17347:18:05

running SlapOS.Eggs.UnitTest-Jerome.Python3

17347:17:59

running SlapOS.SlapRunner.ResilienceTest-Master

17347:18:11

running SlapOS.SoftwareReleases.IntegrationTest-Master

17347:18:34

running Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

17347:18:56