ipalib.config: Only convert basedn to DN

The current code would convert values to DN if the key was
a substring of 'basedn', e.g. 'base' or 'sed'.

Only convert if we're actually dealing with 'basedn'.

Reviewed-By: Fraser Tweedale <ftweedal@redhat.com>

ipalib/config.py

@@ -257,7 +257,7 @@ class Env(object):
                 value = m[value]
             elif value.isdigit():
                 value = int(value)
-            elif key in ('basedn'):
+            elif key == 'basedn':
                 value = DN(value)
             else:
                 try: