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

17324:30:18

running ERP5.StandaloneDeploymentScriptTest-Debian.Buster.Master

17324:30:00

running SlapOS.Eggs.UnitTest-Jerome.Python2

17324:29:40

running SlapOS.Eggs.UnitTest-Jerome.Python3

17324:29:35

running SlapOS.SlapRunner.ResilienceTest-Master

17324:29:46

running SlapOS.SoftwareReleases.IntegrationTest-Master

17324:30:10

running Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

17324:30:31