ldap.LdapClient: make get_attr case-insensitive on attribute name

mylib/ldap.py

@@ -448,6 +448,11 @@ class LdapClient:
                            returned instead of the first value only
                            (optinal, default: False)
         """
+        if attr not in obj:
+            for k in obj:
+                if k.lower() == attr.lower():
+                    attr = k
+                    break
         vals = obj.get(attr, [])
         if vals:
             return vals if all_values else vals[0]