Some more demandimport ignores

mercurial_keyring.py

@@ -53,6 +53,9 b' from mercurial.demandimport import ignor'
 if "gobject._gobject" not in ignore:
     ignore.append("gobject._gobject")
     ignore.append("configparser")
+    ignore.append("json")
+    ignore.append("abc")
+    ignore.append("io")
 
 import keyring
 from urlparse import urlparse