bookmark: fix invalidation of localrepo._bookmarkcurrent stable

bookmark: fix invalidation of localrepo._bookmarkcurrent

--- a/mercurial/localrepo.py	Wed Mar 02 14:09:06 2011 +0100
+++ b/mercurial/localrepo.py	Wed Mar 02 21:57:20 2011 -0600
@@ -763,7 +763,7 @@
         self._branchcachetip = None
 
     def invalidate(self):
-        for a in ("changelog", "manifest", "_bookmarks", "_bookmarkscurrent"):
+        for a in ("changelog", "manifest", "_bookmarks", "_bookmarkcurrent"):
             if a in self.__dict__:
                 delattr(self, a)
         self.invalidatecaches()