MINOR: http_ana: position the FINAL flag for http_after_res execution

MINOR: http_ana: position the FINAL flag for http_after_res execution

Ensure that the ACT_OPT_FINAL flag is always set when executing actions
from http_after_res context.

This will permit lua functions to be executed as http_after_res actions
since hlua_ctx_resume() automatically disables "yielding" when such flag
is set: the hlua handler will only allow 1shot executions at this point
(lua or not, we don't wan't to reschedule http_after_res actions).