tests: fix test_user_permissions.py::TestInstallClientNoAdmin
    
    Adapt the test to ipa-4-6 branch. On this branch, the calls to external
    commands are logged with
    ---8<---
    Starting external process
    args=/usr/bin/getent passwd testuser1@domain.com
    ---8<---
    
    while on master branch the logs are
    ---8<---
    Starting external process
    args=['/usr/bin/getent', 'passwd', 'testuser1@domain.com']
    ---8<---
    
    This is because 9c2c3df was not backported to ipa-4-6 branch and modified
    the debug logs when calling ipautil.run()
    
    Reviewed-By: Francisco Trivino <ftrivino@redhat.com>
    Reviewed-By: Armando Neto <abiagion@redhat.com>