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

16233:34:30

running ERP5.StandaloneDeploymentScriptTest-Debian.Buster.Master

16233:34:12

running SlapOS.Eggs.UnitTest-Jerome.Python2

16233:33:53

running SlapOS.Eggs.UnitTest-Jerome.Python3

16233:33:47

running SlapOS.SlapRunner.ResilienceTest-Master

16233:33:59

running SlapOS.SoftwareReleases.IntegrationTest-Master

16233:34:22

running Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

16233:34:44