py3: explicitly convert dict.values() to a list on py3

dict.values() returns a dict_values() object, so we need to pass it into
list() explicitly to get one.

mercurial/cmdutil.py

@@ -452,7 +452,7 b' def findcmd(cmd, table, strict=True):'
         raise error.AmbiguousCommand(cmd, clist)
 
     if choice:
-        return choice.values()[0]
+        return list(choice.values())[0]
 
     raise error.UnknownCommand(cmd, allcmds)