[MINOR] http: make some room in the transaction flags to extend cookies

We'll need one more bit to store and report the request cookie's status.
Doing this required moving a few bits around. However, now in 1.4 all bits
are used, there's no room left.

Cookie flags will need
(cherry picked from commit 09ebca0413c43620ddc375b5b4ab31a25d47b3f4)
1 file changed