Make use of the single configuration point for the default shells

For now all the default shells of users and admin are hardcoded in
different parts of the project. This makes it impossible to run the
test suite against the setup, which has the default shell differed
from '/bin/sh'.

The single configuration point for the shell of users and admin is
added to overcome this limitation.

Fixes: https://pagure.io/freeipa/issue/7978
Signed-off-by: Stanislav Levin <slev@altlinux.org>
Reviewed-By: Christian Heimes <cheimes@redhat.com>

ipaserver/plugins/migration.py

@@ -38,6 +38,7 @@ from ipapython.ipautil import write_tmp_file
 from ipapython.kerberos import Principal
 import datetime
 from ipaplatform.paths import paths
+from ipaplatform.constants import constants as platformconstants
 
 if six.PY3:
     unicode = str
@@ -233,7 +234,8 @@ def _pre_migrate_user(ldap, pkey, dn, entry_attrs, failed, config, ctx, **kwargs
         entry_attrs['homedirectory'] = home_dir
 
     if 'loginshell' not in entry_attrs:
-        default_shell = config.get('ipadefaultloginshell', [paths.SH])[0]
+        default_shell = config.get('ipadefaultloginshell',
+                                   [platformconstants.DEFAULT_SHELL])[0]
         entry_attrs.setdefault('loginshell', default_shell)
 
     # do not migrate all attributes