changelog: hexlify node when throwing a LookupError on a filtered node

The non-hexlified node was leaking all the way out to the web
interface, and wasn't consistent with the behavior for nonexistent
nodes.

mercurial/changelog.py

@@ -183,7 +183,7 b' class changelog(revlog.revlog):'
         """filtered version of revlog.rev"""
         r = super(changelog, self).rev(node)
         if r in self.filteredrevs:
-            raise error.LookupError(node, self.indexfile, _('no node'))
+            raise error.LookupError(hex(node), self.indexfile, _('no node'))
         return r
 
     def node(self, rev):