Small fix related to VIM Tip #436

http://vim.wikia.com/wiki/Recover_from_accidental_Ctrl-U

Suppose you do the following:

div.foo.bar.baz<c-y>,

This will be expanded to <div clas="foo bar baz"></div>

Then you realize that you wanted yyy instead of baz. You press ESC and
u and notice that you don't have your original string in the undo log
(div.foo.bar.baz).

This patch fixes this behaviour.