[ldapfeed] use LDAP_SCOPES to find user-scope

We already have LDAP_SCOPES dict defining possible scopes, this avoid possible code injection from config...
Thus we can drop global variables already defined in LDAP_SCOPES since they are not used directly anymore.

--HG--
branch : 3.26

cubicweb/server/sources/ldapfeed.py

@@ -34,12 +34,10 @@ from cubicweb.server.sources import datafeed
 from cubicweb import _
 
 # search scopes
-BASE = ldap3.SEARCH_SCOPE_BASE_OBJECT
-ONELEVEL = ldap3.SEARCH_SCOPE_SINGLE_LEVEL
-SUBTREE = ldap3.SEARCH_SCOPE_WHOLE_SUBTREE
-LDAP_SCOPES = {'BASE': BASE,
-               'ONELEVEL': ONELEVEL,
-               'SUBTREE': SUBTREE}
+LDAP_SCOPES = {'BASE': ldap3.SEARCH_SCOPE_BASE_OBJECT,
+               'ONELEVEL': ldap3.SEARCH_SCOPE_SINGLE_LEVEL,
+               'SUBTREE': ldap3.SEARCH_SCOPE_WHOLE_SUBTREE}
+
 
 # map ldap protocol to their standard port
 PROTO_PORT = {'ldap': 389,
@@ -199,7 +197,7 @@ You can set multiple groups by separating them by a comma.',
         self.cnx_dn = typedconfig['data-cnx-dn']
         self.cnx_pwd = typedconfig['data-cnx-password']
         self.user_base_dn = str(typedconfig['user-base-dn'])
-        self.user_base_scope = globals()[typedconfig['user-scope']]
+        self.user_base_scope = LDAP_SCOPES[typedconfig['user-scope']]
         self.user_login_attr = typedconfig['user-login-attr']
         self.user_default_groups = typedconfig['user-default-group']
         self.user_attrs = {'dn': 'eid', 'modifyTimestamp': 'modification_date'}