#44 Handling some more mercurial versions in demandimport logic.

mercurial_keyring.py

@@ -78,8 +78,12 b' try:'
     is_demandimport_enabled = demandimport.isenabled
 except AttributeError:
     # Mercurial < 2.9.1
+    try:
+        orig_demandimport = demandimport.demandimport
+    except AttributeError:
+        orig_demandimport = demandimport._demandimport
     def is_demandimport_enabled():
-        return __import__ == demandimport.demandimport
+        return __import__ == orig_demandimport
 
 # Shut up warning about uninitialized logging for new keyring versions
 import logging