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

17228:43:50

running ERP5.StandaloneDeploymentScriptTest-Debian.Buster.Master

17228:43:31

running SlapOS.Eggs.UnitTest-Jerome.Python2

17228:43:12

running SlapOS.Eggs.UnitTest-Jerome.Python3

17228:43:07

running SlapOS.SlapRunner.ResilienceTest-Master

17228:43:18

running SlapOS.SoftwareReleases.IntegrationTest-Master

17228:43:42

running Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

17228:44:03